Support old wife following dissolution (5)
I believe the answer is:
endow
'support' is the definition.
(thesaurus)
'old wife following dissolution' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'wife' becomes 'w'.
'following' is a charade indicator (letters next to each other).
'dissolution' becomes 'end' (I've seen this in other clues).
'o'+'w'='ow'
'ow' put after 'end' is 'ENDOW'.
(Other definitions for endow that I've seen before include "provide permanent finance for ..." , "supply" , "Settle permanent income on" , "Provide as a gift" , "Provide with an income, say a college" .)