Drop awful crude joke, finally (6)
I believe the answer is:
reduce
'drop' is the definition.
(thesaurus)
'awful crude joke finally' is the wordplay.
'awful' indicates anagramming the letters.
'finally' indicates one should take the final letters.
The final letter of 'joke' is 'e'.
'crude' is an anagram of 'reduc'.
'reduc'+'e'='REDUCE'
(Other definitions for reduce that I've seen before include "Diminish" , "diet" , "subdue" , "Bring down" , "Decrease" .)