Live together (2,7)
I believe this is a double definition.
'live' is the first definition.
(I've seen this before)
'together' is the second definition.
(I know that together can be written as in concert)
(Other definitions for in concert that I've seen before include "Together and combined - at musical performance?" , "on stage?" , "All together, in combination - while performing?" , "Acting together" , "Showing teamwork" .)
'live together' is the definition.
(synonyms)
This is all the clue.
(Other definitions for cohabit that I've seen before include "16 ac 17 ac" , "become bedfellows" , "Live together as unmarried couple" , "Share residence" , "What some items do" .)