Modest teas prepared after church (6)
I believe the answer is:
chaste
'modest' is the definition.
(thesaurus)
'teas prepared after church' is the wordplay.
'prepared' indicates anagramming the letters.
'after' means one lot of letters go next to another.
'church' becomes 'ch' (common abbreviation**).
'teas' with letters rearranged gives 'aste'.
'aste' put after 'ch' is 'CHASTE'.
(Other definitions for chaste that I've seen before include "Modest and decent" , "Continent" , "Cheats (anag.)" , "Maidenly" , "Morally pure" .)