criterion
     n 1: a basis for comparison; a reference point against which
          other things can be evaluated; "they set the measure for
          all subsequent work" [syn: {standard}, {measure}, {touchstone}]
     2: the ideal in terms of which something can be judged; "they
        live by the standards of their community" [syn: {standard}]
     [also: {criteria} (pl)]
Source: WordNet® 2.0