Separate and rest on top of mountain? (5,2)
I believe the answer is:
break up
'separate' is the definition.
(synonyms)
'rest on top of mountain?' is the wordplay.
'rest' becomes 'break' (I've seen this before).
'on top of mountain?' becomes 'up' (up a mountain).
'break'+'up'='BREAK-UP'
'and' is the link.
(Other definitions for break up that I've seen before include "ahead after run of successful pots" , "Bring to an end - or shatter" , "Finish school or a relationship" , "Separate" , "A split" .)