Nothing about a claw (4)
I believe the answer is:
nail
'claw' is the definition.
(thesaurus)
'nothing about a' is the wordplay.
'nothing' becomes 'nil' ('nil' can be a synonym of 'nothing').
'about' is an insertion indicator.
'nil' going around 'a' is 'NAIL'.
(Other definitions for nail that I've seen before include "It needs a hammer (or a file?)" , "'For want of a . . . . the shoe was lost'" , "Covering on tip of the finger" , "Apprehend" , "Hit this on the head to be bang on" .)