Force could, possibly (5)
I believe the answer is:
might
I believe this is a double definition.
'force' is the first definition.
(thesaurus)
'could possibly' is the second definition.
(I've seen this before)
(Other definitions for might that I've seen before include "Capability" , "Clout" , "Powerfulness" , "Great power, strength" , "Physical strength of old" .)