1 A competitive trial of speed in running, swimming, driving, etc; more generally, any manifestation of rivalry or contest. See also arms race.
2 In biology, a taxonomic group into which a species is divided, arising from relative reproductive isolation of populations from one another owing to geographic and other barriers, containing organisms that are genetically differentiable from other members of the same species by the relative frequencies of their polymorphic genes. Thus in humans the relative percentages of the A, B, and O blood group alleles are 28, 6, 66 in Caucasian populations; 18, 11, and 71 in African populations; and 19, 17, and 64 in Oriental populations; and many other polymorphic genes show similar racial differences, but across all polymorphic genes, only about 6 per cent of genetic variance among humans is due to racial differences. Also called a microspecies, subspecies or variety. See also ethnic, racialism, racism. racial adj. [From Italian razza, origin uncertain]