Clay pit being worked over in no way unusual (7)
I believe the answer is:
typical
'in no way unusual' is the definition.
(I know that typical is the opposite attribute of atypic)
'clay pit being worked' is the wordplay.
'being worked' is an anagram indicator.
'clay'+'pit'='claypit'
'claypit' anagrammed gives 'TYPICAL'.
'over' acts as a link.
(Other definitions for typical that I've seen before include "Archetypal" , "routine" , "Having the essential characteristics of a group" , "Characteristic, usual" , "Normal" .)