Yank, tug (4)
I believe the answer is:
pull
This clue is a double definition.
'yank' is the first definition.
(I know that yank is a more specific form of the action pull)
'tug' is the second definition.
(I know that tug is a more specific form of the action pull)
(Other definitions for pull that I've seen before include "Influence; draw" , "Influence; haul on" , "Damage (a muscle)" , "Attract as a customer" , "Tell that to the marines" .)