against |əˈgenst; əˈgānst|
1 in opposition to : the fight against crime | he decided against immediate publication | swimming against the tide.
• in opposition to, with reference to legal action : allegations against police officers | the first victim gave evidence against him.
• in opposition to, with reference to an athletic contest : the championship game against Virginia.
• (in betting) in anticipation of the failure of : the odds were 5–1 against Pittsburgh.
2 in anticipation of and preparation for (a problem or difficulty) : insurance against sickness and unemployment.
• in resistance to; as protection from : he turned up his collar against the wind.
• in relation to (an amount of money owed or due) so as to reduce or cancel it : money was advanced against the value of the property.
3 in conceptual contrast to : the benefits must be weighed against the costs | the instilling of habits as against the development of understanding.
• in visual contrast to : he was silhouetted against the light of the window.
4 in or into physical contact with (something), typically so as to be supported by or collide with it : she stood with her back against the door | his lips brushed against her hair.
have something against someone dislike or bear a grudge against someone : I have nothing against you personally.
ORIGIN Middle English : from again + -s (adverbial genitive) + -t probably by association with superlatives (as in amongst).