Puritanical tea-user soused (7)
I believe the answer is:
austere
'puritanical' is the definition.
(thesaurus)
'tea-user soused' is the wordplay.
'soused' indicates an anagram (a drunken or soused version of the letters).
'tea'+'user'='teauser'
'teauser' anagrammed gives 'AUSTERE'.
(Other definitions for austere that I've seen before include "Severe, ascetic" , "severely self-disciplined" , "Stern, grave" , "Severe in manner" , "not of luxury type" .)