A rifle or small arm weapon with the magazine area behind the trigger group intended to reduce the length of the said weapon but retaining the standard rifle barrel length. The SA80 is an example of this type of design.
The first Bullpup rifle designed for the British Army was a re-worked Enfield around 1911. It was never adopted because, amongst many other good reasons, the army found themselves a little busy from 1914 on. The British No9 and Australian KAL1 are examples of Bullpup rifles.