Phản đối, đối lập, chống lại

Địch thủ, đối thủ, kẻ thù

a political opponent

đối thủ chính trị

đối phương

Antagonist, adversary, disputant, contestant, competitor,contender, rival, foe, enemy; the opposition: He may be myopponent in the chess competition, but we are the best offriends.

N. a person who opposes or belongs to an opposingside.

Adj. opposing, contrary, opposed.

Opponent muscle amuscle enabling the thumb to be placed front to front against afinger of the same hand.

Opponency n. [L opponere opponent-(as OB-, ponere place)]