I can't chew caper (5)
I believe the answer is:
antic
'caper' is the definition.
(synonyms)
'i can't chew' is the wordplay.
'chew' indicates an anagram (I've seen 'chewed' mean this).
'i'+'cant'='icant'
'icant' anagrammed gives 'ANTIC'.
(Other definitions for antic that I've seen before include "Frolic" , "Ludicrous act done for fun" , "Playful caper" , "Caper, trick" , "Eccentric once" .)