Candidate, sensitive after hoax (9)
I believe the answer is:
contender
'candidate' is the definition.
(I've seen this before)
'sensitive after hoax' is the wordplay.
'sensitive' becomes 'tender' (synonyms).
'after' means one lot of letters go next to another.
'hoax' becomes 'con'.
'tender' put after 'con' is 'CONTENDER'.
(Other definitions for contender that I've seen before include "Candidate" , "No red cent (anag.)" , "One fighting others (for something)" , "One struggling" , "Struggler in rivalry" .)