Snapped about forty winks (3)
I believe the answer is:
nap
'forty winks' is the definition.
(synonyms)
'snapped about' is the wordplay.
'about' says the answer is hidden in the clue (the clue goes around or about the answer).
'NAP' is hidden within 'snapped'.
(Other definitions for nap that I've seen before include "Siesta" , "Raised surface of a fabric and short sleep" , "A short sleep or snooze" , "soft, fluffy surface" , "Sleep briefly" .)