1 being an opponent to sb/sth in a game, competition, etc, or an enemy of sb/sth in a war or fight 为…的对手或敌人: We played football against a school from another district. 我们跟别的区的一所学校踢了一场足球。

2 not agreeing with or supporting sb/sth 不赞成；不支持；反对: Are you for or against the plan? 你赞成还是反对这个计划？She felt that everybody was against her. 她觉得人人都在跟她作对。

3 what a law, rule, etc says you must not do 违法；违章；违规: It's against the law to buy cigarettes before you are sixteen. 未满十六岁购买香烟是违法的。

4 to protect yourself from sb/sth 抵抗；抵御；防范: Take these pills as a precaution against malaria. 要服用这些药丸以预防疟疾。

5 in the opposite direction to sth 逆着: We had to cycle against the wind. 当时我们必须逆着风骑自行车。

6 touching sb/sth for support 倚靠；靠: I put the ladder against the wall. 我把梯子靠在墙上。