Fixing chain etc on wheel finally is complex (9)
I believe the answer is:
technical
'is complex' is the definition.
(thesaurus)
'fixing chain etc on wheel finally' is the wordplay.
'fixing' indicates an anagram.
'on' means one lot of letters go next to another.
'finally' says to take the final letters.
The final letter of 'wheel' is 'l'.
'chain'+'etc'='chainetc'
'chainetc' is an anagram of 'technica'.
'technica'+'l'='TECHNICAL'
(Other definitions for technical that I've seen before include "sort of college" , "- Drawing; - foul" , "Requiring special knowledge to be understood" , "Requiring specialist knowledge" , "as per strict rules" .)