What does grep stand for?

[cmeyer at MIT.EDU (Chris Meyer)]

Why does it have to stand for anything? I've always liked to think of it 
as the sound my computer makes when it tries to sort through all the 
files I hand it with "grep -r". (grep grep grep grep grep ding! grep 
grep grep ding!)

I've also seen it expanded to "GNU Regular Expression Parser," although 
it probably didn't start out that way and so the prior responses are 
probably more correct.