Quashed each urge to adopt one vulgarity (9)
I believe the answer is:
gaucherie
'vulgarity' is the definition.
(thesaurus)
'quashed each urge to adopt one' is the wordplay.
'quashed' indicates anagramming the letters (quash can mean to smash up).
'to adopt' is an insertion indicator.
'one' becomes 'I' (Roman numeral).
'each'+'urge'='eachurge'
'eachurge' anagrammed gives 'gauchere'.
'gauchere' going around 'i' is 'GAUCHERIE'.
(Other definitions for gaucherie that I've seen before include "Slip" , "Socially awkward acts - huge Erica (anag)" , "clumsy behaviour" , "clumsiness" , "Awkwardness" .)