Binomial \Bi*no"mi*al\, n. [L. bis twice + nomen name: cf. F. binome, LL. binomius (or fr. bi- + Gr. ? distribution ?). Cf. Monomial.]

(Alg.) An expression consisting of two terms connected by the sign plus (+) or minus (-); as, a + b, or 7 - 3.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Binomial \Bi*no"mi*al\, a.

1. Consisting of two terms; pertaining to binomials; as, a binomial root.

2. (Nat. Hist.) Having two names; -- used of the system by which every animal and plant receives two names, the one indicating the genus, the other the species, to which it belongs.

Binomial theorem (Alg.), the theorem which expresses the law of formation of any power of a binomial.

Source: Webster's Revised Unabridged Dictionary (1913)