Trinomial /(?)/

Tri·no·mi·al

Trinomial

n.
  1. A quantity consisting of three terms, connected by the sign + or -; as, x + y + z, or ax + 2b - c2. (Math.)

Trinomial

a.
  1. Consisting of three terms; of or pertaining to trinomials; as, a trinomial root. (Math.)
  2. Consisting of, or involving the use of, three terms; as, a trinomial systematic name specifying the genus, species, and variety. (Nat. Hist.)