Compel, coerce (5)
I believe the answer is:
force
I believe this is a double definition.
'compel' is the first definition.
(I know that force is a more specific form of compel)
'coerce' is the second definition.
(I know that coerce can be written as force)
(Other definitions for force that I've seen before include "Vehemence" , "Strength - compulsion" , "Muscle" , "Violence" , "fall" .)