Who says? (5)
I believe the answer is:
simon
'who says?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for simon that I've seen before include "See 1" , "He's simple in rhyme" , "Apostle Peter's other name" , "Fellow" , "- Bol'var, S. American liberator" .)