adversary

A person, group, or force that opposes or competes against another; an opponent in a conflict or contest.

• adversarial/ˌædvərˈsɛəriəl/(adj)对抗性的

• formidable adversary
• political adversary
• worthy adversary
• face an adversary
• defeat an adversary

1. 1.In court, the two lawyers were fierce adversaries, but outside they shared a mutual respect. (legal)
2. 2.Climate change is an adversary that no single nation can defeat alone. (figurative)

• opponent/əˈpoʊnənt/— neutral, in competition or debate
• rival/ˈraɪvəl/— someone competing for the same goal
• antagonist/ænˈtæɡənɪst/— someone who actively opposes, often in narrative

from Latin "adversarius" (opponent) — "adversus" (turned against) — ad- (toward) + vertere (to turn)