[bi.no.mi.al] n [NL binomium, fr. ML, neut. of binomius having two names, alter. of L binominis, fr. bi- + nomin-, nomen name--more at name] (1557) 1: a mathematical expression consisting of two terms connected by a plus sign or minus sign
2: a biological species name consisting of two terms -- binomial adj -- bi.no.mi.al.ly adv