Sceptic brewed this tea (7)
I believe the answer is:
atheist
'sceptic' is the definition.
(I've seen this before)
'brewed this tea' is the wordplay.
'brewed' indicates anagramming the letters.
'this'+'tea'='thistea'
'thistea' is an anagram of 'ATHEIST'.
(Other definitions for atheist that I've seen before include "God denier" , "One who believes there is no god" , "Unbeliever" , "Non-believer in god - hates it (anag)" , "Person who believes there is no God" .)