Going Liquid
If you are running (using) CO2 as opposed to air, CO2 is stored in its liquid form and then fed into the marker, changing phase to gas. Some markers cannot handle liquid in their systems and when they `go liquid' the result is either a very `hot' shot or a mess of paint.

Guppy
see Loader

Haddawayandshite
A term from the North East of England hurled by irate players at judges when they feel they’ve received a bad call

Hammer
The hammer strikes the exhaust valve to release a blast of gas to propel the paintball.

Hedger
Literally, ‘one who inhabits a hedge.’ Term coined to describe scruffy, unkempt members of the Paintball fraternity.

Hopper
This refers to someone '`marked' (see mark) on his or her ingrown toe-nail. It sometimes also refers to the plastic holder of paintballs that sits on top of your marker. Hoppers come in different capacities and are either motorised or non-motorised. Motorised hoppers use either a light sensor (activated by a lack of paintballs in the elbow) or are linked to the trigger of the marker (and are activated by trigger action).
A shot that is over the velocity limit.