About to go to Scottish island as one out of the rat race? (7)
I believe the answer is:
retiree
'one out of the rat race?' is the definition.
'about to go to scottish island' is the wordplay.
'about' becomes 're' (regarding**).
'to go to' is a charade indicator (letters next to each other).
'scottish island' becomes 'tiree' (island of the Inner Hebrides).
're'+'tiree'='RETIREE'
'as' is the link.
(Other definitions for retiree that I've seen before include "Someone no longer working" , "One put out to pasture" , "One stopping work" , "One no longer working" , "One having completed work" .)