Garbo for one married in southeast (5)
I believe the answer is:
swede
'garbo' is the definition.
(Greta Garbo was Swedish)
'one married in southeast' is the wordplay.
'one married' becomes 'wed' (wed can mean married).
'in' indicates putting letters inside.
'southeast' becomes 'SE' (synonyms).
'wed' going within 'se' is 'SWEDE'.
'for' acts as a link.
(Other definitions for swede that I've seen before include "N European" , "Foreigner" , "Person like Strindberg" , "North European" , "Cattle fodder" .)