Sharp, expert playing crib (7)
I believe the answer is:
acerbic
'sharp' is the definition.
(synonyms)
'expert playing crib' is the wordplay.
'expert' becomes 'ace' (ace can informally mean very good).
'playing' indicates an anagram.
'crib' is an anagram of 'rbic'.
'ace'+'rbic'='ACERBIC'
(Other definitions for acerbic that I've seen before include "Bitter, sour" , "Bitter in taste -- harsh in tone" , "Sour; sharp" , "Cutting" , "Acrimonious" .)