A minor route out of the country (6)
I believe the answer is:
abroad
'out of the country' is the definition.
(I've seen this before)
'a minor route' is the wordplay.
'minor route' becomes 'broad' (B-road).
'a'+'broad'='ABROAD'
(Other definitions for abroad that I've seen before include "At large - overseas" , "in France, say" , "out of UK?" , "Out of doors - in foreign parts" , "Away from home" .)