Power or force (5)
I believe the answer is:
might
I believe this is a double definition.
'power' is the first definition.
(I know that power can be written as might)
'force' is the second definition.
(might can mean power or force)
(Other definitions for might that I've seen before include "- - and main" , "Great power, strength" , "Force; could" , "Physical strength of old" , "intensity of feeling" .)