Curtsy (3)
I believe the answer is:
'curtsy' is the definition.
(I know that curtsy is a more specific form of the action bow)
This is all the clue.
(Other definitions for bow that I've seen before include "Front - show reverence" , "Make reverence" , "The archer's weapon." , "Incline respectfully; a weapon" , "Bend; knot; weapon" .)