• (a.) Of or pertaining to two names; binomial.
Bi·nom'i·nal adjective [ See Binomial .] Of or pertaining to two names; binomial. 
In algebra, a binominal is a quantity consisting of two terms or members, connected by the sign + or -. The binomial theorem, is the celebrated theorem given by Sir Isaac Newton for raising a binomial to any power, or for extracting any root of it by an approximating infinite series.