The couple care about backing off (4)
I believe the answer is:
both
'the couple' is the definition.
(thesaurus)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for both that I've seen before include "Two considered together" , "The two (things)" , "couple" , "Each of two (alternatives)" , "The one and the other" .)