\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.

\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.