Bow of sailing boat in outline (6)
I believe the answer is:
sketch
'outline' is the definition.
(synonyms)
'bow of sailing boat' is the wordplay.
'bow of' says to take the initial letters (front of).
'boat' becomes 'ketch' (ketch is a kind of sailing vessel).
The initial letter of 'sailing' is 's'.
's'+'ketch'='SKETCH'
'in' acts as a link.
(Other definitions for sketch that I've seen before include "Delineate" , "Simple drawing" , "Make rough drawing" , "Basic drawing" , "Short dramatic scene" .)