Sailor's salutation (4)
I believe the answer is:
ahoy
'sailor's salutation' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ahoy that I've seen before include "What a sailor may" , "The sailor cries ''ship . . . .''" , "Hailing term at sea" , "Call for ship's attention" , "(Nautical) hailing call" .)