Visual pun (5)
I believe the answer is:
rebus
'visual pun' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for rebus that I've seen before include "Ian Rankin's Scottish detective" , "Visual type of word puzzle" , "Word puzzle involving pictures" , "Word puzzle with pictures and letters" , "Puzzle consisting of pictures representing syllables and words" .)