Bullpup

A FAMAS G2 (with bayonet). Notice the handgrip in front of the breech.
(Credit: Wikipedia user Rama)
This is a configuration for a firearm where the handgrip is in front of the breech. This tends to make for a shorter weapon overall, while preserving barrel length and muzzle velocity.
No one quite knows or can agree where the name “bullpup” originated. It might have something to do with the “squat” appearance of bulldog puppies.
Why I Looked It Up
I ran across it when researching muzzle velocity at the link above.