Orderly welcomes ordinary sailor (7)
I believe the answer is:
boatman
'sailor' is the definition.
(I've seen this before)
'orderly welcomes ordinary' is the wordplay.
'orderly' becomes 'batman' (batman can mean an orderly or servant).
'welcomes' is an insertion indicator (in sense of 'invites in').
'ordinary' becomes 'O' (abbreviation e.g. O-Levels).
'batman' placed around 'o' is 'BOATMAN'.
(Other definitions for boatman that I've seen before include "George - or Harris, maybe" , "One having row with" , "Water transport provider" , "Sailor" , "He may have a smack" .)