I'm sure lots of theses have already been mentioned but I'll go down my list:
Roles:
Hullgineer - The hull engineer on any given ship.
Gungineer - Secondary engineer.
Ships:
Metamidion - Gat/Flak Pyramidion
Mortarmidion - Mortar/Gat Pyramidion
Ramidion- A Pyramidion built with the purpose of ramming, usually double Gat.
Flakfish - Heavy flak main gun goldfish.
Lumberfish - Lumberjack main gun goldfish.
Blenderfish - Carronaide main gun goldfish.
Hwatchafish - Hwatcha main gun goldfish.
Drive by Squid - A squid that uses flares and Mercs to fly in, mess up the enemy and get a few shots in on the way out. Useful as a distraction.
Dragonfire Galleon - Double Lumber/Merc side, Double Hwatcha side.
Maneuvers:
Sentry - Act as a guard for your allied vessel.
Support - Act as a disable for your allied vessel.
Kiting - Positioning your ship so as to avoid fire.
Rushing - Moving toward your opponent in a very aggressive manner.
Trifecta - Positioning your Pyramidion on an angle so as to allow three light guns to have a firing arc.
Salt 'n Peppa - Maneuvering your ship between firing arcs to allow maximum damage, used in squids and goldfish.
Teabag - Ramming from above.
GOODNIGHT KISS - A timed light ram by a pyramidion making use of its gunfire to deal most of the dmg and gaining the kill with the light touch.
Feathering - Positioning your ship within firing arc and alternating throttle speeds to maintain optimal distance for damage.
Balls Deep - Over extending your position.
Meat Grinding - Engaging back to back one versus two (or more) fights resulting in your loss.
Players:
Swab - New player
Vet - Old player
Tryhard - Someone who is focused on winning.
Scrub - Someone who is not focused on winning.
General:
Meta - The most well known build/strategy used widely by Swabs.
MOBA - Multiplayer Online Battle Arena
Rolled - Completely defeated without hope.
Ragequit - Leaving a match due to frustration.