Crush bowl made of clay (not hard) (10)
I believe the answer is:
dishearten
'crush' is the definition.
'bowl made of clay not hard' is the wordplay.
'bowl' becomes 'dish' (I've seen this before).
'made of clay' becomes 'earthen' (I've seen this before).
'not' indicates named letters should be taken away.
'hard' becomes 'h'.
'earthen' with 'h' removed is 'earten'.
'dish'+'earten'='DISHEARTEN'
(Other definitions for dishearten that I've seen before include "Bring down" , "Take away bottle" , "Take hope from" , "Cause (someone) to lose confidence" , "dismay?" .)