Put forth, as force (5)
I believe the answer is:
exert
'put forth as force' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for exert that I've seen before include "Wield - apply" , "Act upon" , "Strive" , "Bring quality or influence into play" , "Bring into use, say strength" .)