Approach commercial outlet (6)
I believe the answer is:
advent
'approach' is the definition.
(I've seen this before)
'commercial outlet' is the wordplay.
'commercial' becomes 'ad' (abbreviation for advertisement).
'outlet' becomes 'vent' (I've seen this before).
'ad'+'vent'='ADVENT'
(Other definitions for advent that I've seen before include "Run-up to Christmas" , "appearance" , "Coming (of Christmas)" , "Period in church calendar" , "Forty days preceding Christmas" .)