Behave obsequiously (3,3,6)
I believe the answer is:
bow and scrape
'behave obsequiously' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for bow and scrape that I've seen before include "show subservience" , "Behave obsequiously" , "Show humility" , "Grovel" , "Two ways to fiddle" .)