Trickery is fashionable — yearn for reform (9)
I believe the answer is:
chicanery
'trickery' is the definition.
(synonyms)
'fashionable yearn for reform' is the wordplay.
'fashionable' becomes 'chic' (chic means stylish or fashionable).
'for reform' is an anagram indicator (I've seen this in other clues).
'yearn' anagrammed gives 'anery'.
'chic'+'anery'='CHICANERY'
'is' acts as a link.
(Other definitions for chicanery that I've seen before include "dishonest practices" , "legal tricks" , "Use of deception for gain" , "deceptive" , "Trickery used to gain advantage, duplicity" .)