That can be put on if it’s fitting (10)
I believe the answer is:
applicable
'it's fitting' is the definition.
(thesaurus)
'that can be put on' is the wordplay.
I cannot quite see how this works, but
'can' could be 'able' (I've seen this in other clues) and 'able' is found in the answer.
This explanation may well be incorrect...
'if' is the link.
Can you help me to learn more?
(Other definitions for applicable that I've seen before include "Suitable" , "Relevant, appropriate" .)