g   A unit of force equal to the gravitational pull exerted by the earth on a
    stationary object.  Accelerating objects (such as an aircraft and its pilot)
    will experience different amounts of g force, depending on the degree to
    which they are accelerating. 
g suit   A suit worn by pilots to counter the physiological effects of high g 
    forces.
GBU   Guided Bomb Unit -- "smart" bomb.
general strike package    A selection of planes designated to attack a
    target.
glareshield   The screen onto which a head-up display is projected.
glide path   The path of descent to landing.
green shirt   An aircraft carrier deckhand whose duties involve readying
    aircraft for launch, securing them to the catapult. 
gun cross    A cross on a head-up display that is used for aiming M61A1
    cannon rounds. 

HARM   High-speed Anti-Radiation Missile, used to destroy radar
    installations.
heading   The direction in which the nose of the airplane points during
    flight.  It is the course corrected for wind.