/ə'genst, ə'geɪnst; ə`ˇɛnst, ə`ˇenst/
prep
1 in opposition to (sb/sth) 逆着; 反对; 违反; 与...相反
*We were rowing against the current. 我们逆水划船.
* Are most people against the proposal? 是多数人都反对这项提议吗?
* That's against the law. 那是违法的.
* She was married against her will. 她结婚是有违本意的.
* His age is against him, ie is a disadvantage to him. 他的年龄于他不利.
2 in contact with (sb/sth); into collision with 触; 碰; 倚; 靠; 撞
*Put the piano there, with its back against the wall. 把钢琴放在那 , 背靠着墙.
* He was leaning against a tree. 他倚着一棵树.
* The rain beat against the car windscreen. 雨点打在汽车挡风玻璃上.
3 in contrast to (sth) 衬托; 相映; 对照; 对比
*silhouetted against the sky 以天空为背景显出轮廓的
* The skier's red clothes stood out clearly against the snow. 滑雪者的红衣服在雪的衬托下显得分外醒目.
* (fig 比喻) The salaries here are low (as) against the rates elsewhere. 这 的薪水与别处相比是很低的.
4 in preparation for (sth); in anticipation of 防备; 预防
*protect plants against frost 保护植物以防霜冻
* take precautions against fire 采取防火措施
* an injection against rabies 狂犬病预防针.
5 opposite (sth), so as to cancel or lessen 抵销; 抵偿; 抵补
*allowances to be set against income 用以抵补总收入的津贴.
6 in return for (sth) 作为...的交换
*What's the rate of exchange against the dollar? 美元的兑换率是多少?
* Tickets are issued only against payment of the full fee. 只有付讫全费才可将票发出.
7 (idm 习语) as against sth => as.

prep
[Date: 1300-1400; Origin: againes 'against' (11-16 centuries), from again]
a) used to say that someone opposes or disagrees with something
　Every council member voted against the proposal.
　those who are campaigning against the new road
　He advised me against travelling.
　Mr Howard has declared that he is against all forms of racism.
　the fight against terrorism
b) used to say that an action is not wanted or approved of by someone
　They got married against her parents' wishes (=although they knew her parents did not want them to) .
　She has been kept in the house against her will (=she does not want to stay in the house) .
　The use of certain drugs is against the law (=illegal) .
　It's against my principles to borrow money (=I do not believe it is right) .
c) used to say that something is not allowed by a law or rule
　There ought to be a law against it.
used to say who someone is competing with or trying to defeat in a game, battle etc
　Gambotti was injured in last Saturday's game against the Lions.
　We'll be competing against some of the best companies in Europe.
used to say who is harmed, threatened, or given a disadvantage
　violence against elderly people
　crimes against humanity
　discrimination against women
　There had been death threats against prison staff.
　Your lack of experience could count against you.
　The regulations tend to work against smaller companies.
used to say that something touches, hits, or rubs a surface
　the sound of the rain drumming against my window
　The car skidded and we could hear the crunch of metal against metal.
next to and touching an upright surface, especially for support
　There was a ladder propped up against the wall.
　The younger policeman was leaning against the bureau with his arms folded.
in the opposite direction to the movement or flow of something
≠ with
　sailing against the wind
　She dived down and swam out strongly against the current.
seen with something else behind or as a background
　He could see a line of figures silhouetted against the sky.
　It is important to know what colours look good against your skin.
used to show that you are considering particular events in relation to other events that are happening at the same time
　The reforms were introduced against a background of social unrest.
used to say what you are comparing something with
　The pound has fallen 10% against the dollar.
　She checked the contents of the box against the list.
　The cost of the proposed research needs to be balanced against its benefits.
used to say who or what you are trying to protect someone or something from
　insurance against accident and sickness
　a cream to protect against sunburn
　a vaccine which is effective against pneumonia
used to say who is said or shown to have done something wrong
　He has always emphatically denied the allegations against him.
　The evidence against you is overwhelming.
be/come up against sb/sth
to have to deal with a difficult opponent or problem
　You see, this is what we're up against - the suppliers just aren't reliable.
have sth against sb/sth
to dislike or disapprove of someone or something
　I don't have anything against babies. I just don't feel very comfortable with them.