"Not even a collar", you say (5)
I believe the answer is:
rough
'not even' is the definition.
'a collar you say' is the wordplay.
'a collar' becomes 'ruff' (ruff is a kind of collar).
'you say' indicates a 'sounds like' (homophone) clue.
'ruff' sounds like 'ROUGH'.
(Other definitions for rough that I've seen before include "Ill" , "Approximate; turbulent" , "Very choppy" , "that driver tries to avoid" , "grating > below par" .)