"Hello, matey!" (4)
I believe the answer is:
ahoy
'hello matey' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ahoy that I've seen before include "Nautical hail" , "Nautical greeting" , "Naval call for attention" , "Hullo, sailor!" , "Shout from sailor" .)