Entertained a married American editor (6)
I believe the answer is:
amused
'entertained' is the definition.
(synonyms)
'a married american editor' is the wordplay.
'married' becomes 'm' (abbreviation, e.g. in genealogy).
'american' becomes 'US' (abbreviation for United States).
'editor' becomes 'ed' (abbreviation).
'a'+'m'+'us'+'ed'='AMUSED'
(Other definitions for amused that I've seen before include "Delighted" , "Mildly entertained by Medusa" , "Victoria reputedly wasn't" , "Tickled pink" , "Provoked mirth in" .)