Answer:

foe

Answer	Crossword Clue
FOE	Adversary
FOE	Hostile force
FOE	Word in a sentry's question

FOE	Rival
FOE	Frenemy, e.g.
FOE	No proponent
FOE	Goldfinger, to Bond
FOE	McCoy, to Hatfield
FOE	Nemesis
FOE	Opposing team
FOE	Sabretooth to Wolverine, e.g.

FOE	Friend's opposite
FOE	Hector, to Achilles
FOE	Moriarty, to Holmes
FOE	Enemy
FOE	Paris, to Romeo
FOE	One not to trust
FOE	Antagonist
FOE	Cassius, to Caesar

FOE	Mr. Mxyzptlk, to Superman
FOE	One opposed
FOE	One who is against you
FOE	One to beat
FOE	Counter person?
FOE	One who isn't behind you
FOE	Sentry's word
FOE	Hardly a follower

FOE	One of them?
FOE	Other side
FOE	Grant, to Lee
FOE	Hatfield, to a McCoy
FOE	Them, often
FOE	One who isn't with us
FOE	Unfriend?
FOE	Burr, to Hamilton

FOE	Competitor
FOE	Military enemy
FOE	One on the other side
FOE	Friend's alternative
FOE	Grendel, to Beowulf

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.