Elderly carrying on is to be suffered (8)
I believe the answer is:
agonised
'be suffered' is the definition.
(I've seen this before)
'elderly carrying on is' is the wordplay.
'elderly' becomes 'aged' ('aged' can be a synonym of 'elderly').
'carrying' is an insertion indicator.
'on'+'is'='onis'
'aged' enclosing 'onis' is 'AGONISED'.
'to' is the link.
(Other definitions for agonised that I've seen before include "Felt mental anguish (over a decision)" , "San Diego (anag) - worried intensely" , "Underwent mental anguish (over something)" , "Suffered mental anguish" , "Struggled" .)