opponent, competitor, enemy, foe, rival

名詞 opponent:

1. a contestant that you are matched against
   同義詞：opposition, opposite
2. someone who offers opposition
   同義詞：adversary, antagonist, opposer, resister

形容詞 opponent:

1. characterized by active hostility
   同義詞：opposing

1. He was assailed by his political opponent.
   他遭到政敵的攻擊。
2. I tried to comfort him after he was defeated by his opponent.
   他被對(duì)手擊敗后，我盡力安慰他。
3. He jeered at a defeated opponent.
   他嘲弄被擊敗的對(duì)手。
4. He is slashing wildly at his opponent with a sword.
   他正用劍瘋狂地朝對(duì)手亂砍。
5. My friend, Crawley, has always been a fanatical opponent of Mr Lane's Radical Progressive Party.
   我的朋友Crawley一直是Lane先生激進(jìn)黨的一名狂熱反對(duì)者。
6. Never underestimate your opponent.
   千萬(wàn)不要低估對(duì)手。
7. She is one of the strongest opponents of tax reform.
   她是稅收改革最強(qiáng)烈的反對(duì)者之一。
8. His opponent did not stand a chance.
   他的對(duì)手毫無(wú)取勝的機(jī)會(huì)。

op.po.nent

n.（名詞）
One that opposes another or others in a battle, contest, controversy, or debate.
對(duì)手：在爭(zhēng)論、辯論、戰(zhàn)爭(zhēng)、對(duì)抗或其它口頭論戰(zhàn)中反對(duì)對(duì)方或其他人的人
adj.（形容詞）
Acting against an antagonist or opposing force:
對(duì)立的：作為反面人物的，反對(duì)的：
例句：
opponent armies.
敵軍

Located in front.
位于前方的，首要的

來(lái)源：
Latin oppônôns oppônent- [present participle of] oppônere [oppose] * see oppose
拉丁語(yǔ) oppônôns oppônent- [] oppônere的現(xiàn)在分詞 [對(duì)抗] *參見(jiàn) oppose

【引伸】
oppo.nency
n.（名詞）
<參考詞匯><同義詞>opponent,adversary,antagonistThese nouns all mean one who offers opposition.Anopponent opposes, resists, or combats:
這些名詞都指持反對(duì)意見(jiàn)的人。一個(gè)opponent 反對(duì)、抵抗或反抗：
例句：
.two men, one . . . a zealous supporter and the other a zealous opponent of the system pursued. (Macaulay).
.兩種人，一種…是對(duì)一種體系的熱心支持者，另一種是激進(jìn)反對(duì)者. （麥考利）。

Adversary suggests a more formidable opponent and can imply animosity:
Adversary 暗含難以對(duì)付的對(duì)手，而且可能產(chǎn)生敵意：
例句：
.the Adversary of God and Man,/Satan . (John Milton).
.上帝和人類(lèi)的對(duì)手/，撒旦 . （約翰·彌爾敦）。

例句：
.And do as adversaries do in law,/Strive mightily, but eat and drink as friends. (Shakespeare).Anantagonist is an actively hostile opponent:
.按法律的要求做事，/勇敢地戰(zhàn)斗，但是要友好地生活. （莎士比亞）。Antagonist 意思是敵意很強(qiáng)烈的反對(duì)者：

例句：
.He that wrestles with us strengthens our nerves, and sharpens our skill.Our antagonist is our helper. (Edmund Burke).See also Synonyms at enemy
.和我們搏斗的對(duì)手使我們士氣大增，而且提高了技巧。我們的對(duì)手是我們的救星. （埃德蒙·伯克）參見(jiàn)同義詞 enemy