Support husband or wife online? (7)
I believe the answer is:
espouse
'support' is the definition.
(I've seen this before)
'husband or wife online?' is the wordplay.
I cannot quite understand how this works, but
'husband' could be 'spouse' (a husband is a male spouse) and 'spouse' is located in the answer.
'online?' could be 'e' (as in e-mail or e-commerce) and 'e' is found in the answer.
No letters remain.
This explanation may well be incorrect...
(Other definitions for espouse that I've seen before include "See opus (anag)" , "Follow and promote a cause" , "Give support to, say a cause" , "Adopt or support, say a cause" , "See opus to support a cause" .)