Woo, in a way (8)
I believe the answer is:
'woo in a way' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for serenade that I've seen before include "Evening music (played outside woman's house)" , "Music appropriate for evening" , "Evening love song" , "composition" , "Suitor's song" .)