Both Uses

antagonist
in
The Crucible
(Edited)

So their self-denial, their purposefulness, their suspicion of all vain pursuits, their hard-handed justice were altogether perfect instruments for the conquest of this space so antagonistic to man.
p. 6.5 *

antagonistic = hostile
Our difficulty in believing the—for want of a better word—political inspiration of the Devil is due in great part to the fact that he is called up and damned not only by our social antagonists but by our own side, whatever it may be.
p. 34.2

antagonists = adversaries (opponents)

Definitions:

(1) (antagonist as in: the antagonist in the film)
someone who offers opposition or is hostile
(2) (meaning too rare to warrant focus)
Specialized Definitions of antagonist:
- literature or storytelling: the most important character who opposes the main character or protagonist
- physiology: a muscle that relaxes when another muscle contracts
- chemistry and biology: a substance that interferes with the effect of another substance