Archaic old university undecided about wife (7)
I believe the answer is:
outworn
'archaic' is the definition.
(thesaurus)
'old university undecided about wife' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'university' becomes 'u'.
'undecided' becomes 'torn' (someone deliberating between two options is torn).
'about' indicates putting letters inside.
'wife' becomes 'w'.
'torn' placed around 'w' is 'tworn'.
'o'+'u'+'tworn'='OUTWORN'
(Other definitions for outworn that I've seen before include "Obsolete, dated" , "Old-fashioned" , "Old, exhausted or no longer used as dress" , "Out of date" , "Jaded" .)