The first letter from boot camp can feel like it was written in a foreign language. Your recruit might mention getting yelled at for gear adrift, sweeping the deck, or counting the days until the Crucible. At graduation you will hear even more new words, and once your son or daughter becomes a Marine, the vocabulary keeps growing. This guide collects the Marine Corps terms and slang parents hear most often, grouped by theme and explained in plain English, so you can follow along, ask better questions, and feel more connected to the journey your Marine is on.
Before Boot Camp: Enlistment Terms
Many families start learning Marine vocabulary months before boot camp, during the time between signing up and shipping out.
- Poolee: A young person who has enlisted but has not yet left for recruit training. Poolees often attend regular workouts and meetings with their recruiter to prepare.
- DEP: Short for Delayed Entry Program, the waiting period between enlisting and shipping to boot camp. You may hear people say your child is “in the DEP” or “in the pool.”
- MEPS: Military Entrance Processing Station. This is where applicants take medical exams and aptitude testing, complete paperwork, and take the oath of enlistment.
- Ship date: The day your future Marine leaves for recruit training.
- Recruiter: The Marine who guides an applicant through enlistment and helps poolees prepare for boot camp.
Boot Camp Terms
These are the words that show up most often in letters home during the roughly 13 weeks of recruit training.
- Recruit: What your son or daughter is called during boot camp. They have not earned the title Marine yet, and calling them one too early is a common parent slip.
- Boot camp: The everyday name for Marine Corps recruit training, held at Marine Corps Recruit Depot Parris Island in South Carolina or Marine Corps Recruit Depot San Diego in California.
- Receiving: The first few days of boot camp, when recruits arrive, get haircuts and uniforms, complete paperwork, and make a short scripted phone call home to say they arrived safely.
- Drill Instructor (DI): The Marines who train, supervise, and mentor recruits around the clock. Recruits address them with great formality.
- Senior Drill Instructor: The lead drill instructor for a platoon. Recruits often describe this person as the steady, fatherly or motherly figure of the team.
- Platoon: The group of recruits your child lives and trains with throughout boot camp.
- “Aye aye, sir” or “Aye aye, ma’am”: The proper response to an order. It means “I understand, and I will carry out the order.”
- The Crucible: A 54-hour field event near the end of boot camp with long hikes, little food, limited sleep, and team challenges. Completing it is when recruits earn the title Marine.
- EGA: The Eagle, Globe, and Anchor, the Marine Corps emblem. Recruits receive one in a ceremony right after the Crucible, a moment many Marines remember for life.
- Family Day: The day before graduation when families can visit with their new Marines on base, often for the first time in months.
- Graduation: The formal ceremony that marks the end of recruit training and the start of life as a Marine.
- Incentive training: Short bursts of intense exercise given by drill instructors as a correction. Your recruit may simply call it “getting IT’d.”
Barracks and Daily Life
The Marine Corps is part of the Department of the Navy, so a lot of everyday language comes from life aboard ships. You will hear these words in boot camp and long after.
- Deck: The floor.
- Bulkhead: A wall.
- Overhead: The ceiling.
- Hatch: A door.
- Head: The bathroom.
- Rack: A bed or bunk. “Hitting the rack” means going to sleep.
- Chow: Food or a meal. The chow hall is where Marines eat.
- Cover: A hat or other uniform headwear. Marines generally do not wear covers indoors.
- Skivvies: Underwear and undershirts.
- Gear adrift: Equipment left lying around or not properly put away. It is a common source of correction for recruits.
- Squared away: Neat, organized, and doing things the right way. Being called squared away is a compliment.
- Field day: A thorough cleaning of living spaces, not a day of games.
- Liberty: Authorized time off, usually allowing a Marine to leave base for a set period.
- Leave: Longer authorized vacation time that Marines earn and can use to travel home.
- Barracks: The buildings where single junior Marines usually live on base.
- High and tight: A classic Marine haircut that is very short on the sides with a little more length on top.
- Scuttlebutt: Rumors or gossip. The word originally referred to a ship’s drinking water barrel, where sailors gathered to talk.
- Charlie Mike: Military radio shorthand for “continue mission.” It is often used to mean keep going or push through.
Ranks and People
Your Marine will mention people by rank or nickname. A few of the most common terms are below.
- Private: The starting enlisted rank for most new Marines.
- NCO: Noncommissioned officer, meaning corporals and sergeants. NCOs are often called the backbone of the Marine Corps because they lead small teams day to day.
- SNCO: Staff noncommissioned officer, meaning enlisted Marines from Staff Sergeant up through the senior enlisted ranks.
- Gunny: A friendly, respected nickname for a Gunnery Sergeant.
- Top: An informal nickname commonly used for a Master Sergeant.
- Sergeant Major: A senior enlisted leader who advises a commander on matters affecting enlisted Marines.
- Officer: A Marine who holds a commission and leads units, from lieutenants up to generals.
- Corpsman: A Navy medical sailor who serves alongside Marines. Marines often call their corpsman “Doc” and hold them in very high regard.
- Chaplain: A Navy chaplain who provides religious and personal support to Marines of all faiths, or none.
Training and Jobs
After graduation, the training continues. These terms help you follow where your Marine is and what they are learning.
- MOS: Military Occupational Specialty, the Marine’s job, identified by a four-digit code.
- SOI: School of Infantry, where new Marines go after boot camp and post-graduation leave for combat training.
- MCT: Marine Combat Training, the course at the School of Infantry for Marines headed into non-infantry jobs. It teaches basic combat skills every Marine needs.
- IMC: Infantry Marine Course, the training at the School of Infantry for Marines who will serve in the infantry.
- MOS school: The follow-on school where a Marine learns the specific skills of their job, such as communications, mechanics, or logistics.
- PFT: Physical Fitness Test, a yearly test that includes pull-ups or push-ups, a plank, and a three-mile run.
- CFT: Combat Fitness Test, a separate yearly test built around combat-related movements, including a sprint course and lifting an ammunition can overhead.
- MCMAP: Marine Corps Martial Arts Program, which teaches hand-to-hand skills along with character and discipline. Marines earn colored belts, starting with tan.
- Rifle qualification: Marksmanship testing that every Marine completes, starting in boot camp. “Every Marine a rifleman” is a core idea in the Corps.
- Duty station: The base where a Marine is assigned after finishing training.
- Deployment: A period when a Marine’s unit is sent away from home base for an assignment, sometimes overseas or aboard ship.
Traditions and Nicknames
Marines take great pride in their history, and that pride shows up in their nicknames and sayings. Most of these are worn as badges of honor.
- Semper Fi: Short for Semper Fidelis, Latin for “Always Faithful,” the Marine Corps motto. It is used as a greeting, a farewell, and a statement of loyalty.
- Oorah: A spirited Marine expression of enthusiasm, agreement, or motivation.
- Moto: Short for motivated. A “moto” Marine shows lots of enthusiasm for the Corps. It can be praise or a gentle tease.
- Boot: A brand-new Marine fresh out of training. It is a lighthearted label that wears off with experience.
- Devil Dog: A proud nickname for Marines that, according to Marine tradition, dates back to World War I and the fighting at Belleau Wood.
- Leatherneck: A nickname that comes from the leather collar worn on early Marine uniforms.
- Jarhead: A common slang nickname for a Marine, often linked to the high and tight haircut. Many Marines use it among themselves with humor.
- Grunt: A Marine in the infantry. Infantry Marines usually say it with pride.
- POG: A playful term infantry Marines sometimes use for Marines in support jobs outside the infantry. It is usually friendly ribbing, and every support role is essential to the mission, so parents should not take it as an insult.
- The Marine Corps Birthday: November 10, celebrated every year with a formal ball, a cake-cutting ceremony, and a reading of the Commandant’s birthday message.
- Dress Blues: The iconic Marine dress uniform, worn for formal events and ceremonies.
- “Once a Marine, always a Marine”: A saying that reflects the belief that the title stays with a person for life, even after they leave active service.
Tips for Using Marine Terms as a Parent
You do not need to speak like a Marine to support one, but a little knowledge goes a long way. Read letters with this list nearby, and do not be afraid to ask your Marine what something means. Most will happily explain. Remember that the title Marine is earned, so wait until after the Crucible to use it. Never call a Marine a soldier, since soldiers serve in the Army. And when in doubt, a sincere “Semper Fi” is always welcome.
Frequently Asked Questions
When can I start calling my child a Marine?
Recruits earn the title Marine when they complete the Crucible and receive their Eagle, Globe, and Anchor near the end of boot camp. Before that, they are recruits. Many families celebrate the first letter or call where they can finally say “my son the Marine” or “my daughter the Marine.”
Why do Marines use Navy words like deck and head?
The Marine Corps is part of the Department of the Navy and has a long history of serving aboard ships. Naval terms became part of daily Marine language, and they are used even on land bases, in buildings, and in the field.
Is “jarhead” an insult?
Not usually. Marines often use it among themselves with good humor. Coming from an outsider, tone matters, so most parents stick with “Marine,” “Devil Dog,” or “Leatherneck” if they want a nickname that is clearly respectful.
What is the difference between SOI, MCT, and IMC?
SOI, the School of Infantry, is where new Marines go after boot camp. Within it, Marines headed to infantry jobs attend the Infantry Marine Course, while Marines headed to other jobs attend Marine Combat Training before moving on to their MOS school.
What should I say to my Marine at graduation?
Simple words mean the most. Tell your Marine you are proud of them and that you saw how hard they worked. A heartfelt “Semper Fi” or “Oorah” will likely earn a smile, but your hug and your presence are what they will remember.