Sailor to reach goal (6)
I believe the answer is:
target
'goal' is the definition.
(I know that target is a type of goal)
'sailor to reach' is the wordplay.
'sailor' becomes 'tar' (slang term for a sailor).
'to reach' becomes 'get' (I've seen this in another clue).
'tar'+'get'='TARGET'
(Other definitions for target that I've seen before include "Thing to aim at" , "Object of attack" , "Aim, objective" , "Fixed goal" , "The object with the bullseye" .)