Conduct oneself (6)
'conduct oneself' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for behave that I've seen before include "Act properly" , "Mind your manners" , "Act appropriately" , "Conduct oneself well" , "Act, conduct oneself" .)
(Other definitions for acquit that I've seen before include "Free (from charge)" , "Release" , "Absolve" , "Declare (someone) not guilty of a crime" , "Declare to be innocent of a crime" .)