Hothead in Chinese secret society gets the lash (5)
I believe the answer is:
thong
'the lash' is the definition.
('thong' can be a synonym of 'lash')
'hothead in chinese secret society' is the wordplay.
'hothead' becomes 'h' (head letter of 'hot').
'in' is an insertion indicator.
'chinese secret society' becomes 'tong' (I've seen this before).
'h' placed inside 'tong' is 'THONG'.
'gets' is the link.
(Other definitions for thong that I've seen before include "flip-flop" , "Skimpy garment" , "Narrow strip of leather (or other material)" , "Sexy strip" , "Leather strip that forms the flexible part of a whip: excuse for underwear" .)