Suggestion husband ignored: discourteous to butt in (7)
I believe the answer is:
intrude
'butt in' is the definition.
(to butt in is to intrude or interrupt)
'suggestion husband ignored discourteous' is the wordplay.
I cannot really see how this works, but
'discourteous' could be 'rude' (I've seen this before) and 'rude' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' acts as a link.
(Other definitions for intrude that I've seen before include "Poke one's nose in" , "Push in uninvited" , "Butt in, interfere" , "Join in without being invited or wanted" , "Encroach on others' privacy" .)