What is "trinomial"

Trinomial \Tri*no"mi*al\, n. [Pref. tri- + -nomial as in binomial: cf. F. trin[^o]me.] (Math.) A quantity consisting of three terms, connected by the sign + or -; as, x + y + z, or ax + 2b - c^ 2.

Trinomial \Tri*no"mi*al\, a.

1. (Math.) Consisting of three terms; of or pertaining to trinomials; as, a trinomial root.

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

1670s, "having three names," from tri- + second element from binomial. In mathematics, "consisting of three terms" (1704).

a. Consisting of three names or parts or terms. n. (context algebra English) An expression consisting of 3 terms.

In elementary algebra, a trinomial is a polynomial consisting of three terms or monomials.