Sarcastic chap cracking jokes? (7)
I believe the answer is:
pungent
'sarcastic' is the definition.
(similar in meaning)
'chap cracking jokes?' is the wordplay.
I cannot quite understand how this works, but
'chap' could be 'gent' (I've seen this in other clues) and 'gent' is found in the answer.
The remaining letters 'pun' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for pungent that I've seen before include "bitter" , "With a sharp taste or smell" , "Incisive" , "Smelly" , "With a fifteen ac smell/taste" .)