Some friends of mine are/were huge Counter Strike fans. I only played it a few times, almost always at lan parties, but thankfully never came across bunny hopping:
If you don’t know what bunny hopping is, a message on this thread linked to the Wikipedia page on the practice.
Bunny hopping, or bunny jumping, is a term used in video games to describe the basic movement technique in which a player jumps repeatedly instead of running in order to move faster and/or to avoid enemy fire.