a·gainst / əˈgenst; əˈgānst/ • prep. 1. in opposition to: swimming against the tide. ∎  in opposition to, with reference to legal action: allegations against police officers. ∎  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 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. ∎  in visual contrast to: 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: his lips brushed against her hair.PHRASES: have something against someone dislike or bear a grudge against someone: I have nothing against you personally.

against opposite (now only in over against); in resistance to XII; contrary to; in return for XIII. ME. aʒeines, aʒaines, aʒens, f. aʒein, etc. + -es, see prec., -S. For the parasitic -t cf. AMIDST, AMONGST.