Against  prep. 1 in opposition to (fight against crime). 2 into collision or in contact with (lean against the wall). 3 to the disadvantage of (my age is against me). 4 in contrast to (against a dark background). 5 in anticipation of (against his coming; against the cold). 6 as a compensating factor to (income against expenditure). 7 in return for (issued against payment of the fee).  against the grain see *grain. Against time see *time. [from *again, with inflectional -s]