Short joke (3-5)
I believe the answer is:
one-liner
'short joke' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for one-liner that I've seen before include "Quick joke?" , "Witty remark in single short sentence" , "Witty remark contained in a single sentence" , "Terse joke" , "Witty remark consisting of a short sentence" .)