Relaxing with others, mostly replete (7)
I believe the answer is:
restful
'relaxing' is the definition.
(I've seen this before)
'with others mostly replete' is the wordplay.
'with' is a charade indicator (letters next to each other).
'others' becomes 'rest' (I've seen this before).
'mostly' means to remove the last letter.
'replete' becomes 'full' ('full' can be a synonym of 'replete').
'full' with its last letter taken off is 'ful'.
'rest'+'ful' is 'RESTFUL'.
(Other definitions for restful that I've seen before include "Sedative" , "Still - calming" , "Tranquil - fluster (anag)" , "Calm" , "Quiet, soothing" .)