[ trahy-noh-mee-uhl ]

  1. Algebra. consisting of or pertaining to three terms.

  2. Biology.

    • pertaining to a scientific name comprising three terms, as of genus, species, and subspecies or variety.

    • characterized by the use of such names.

  1. Algebra. an expression that is a sum or difference of three terms, as 3x + 2y + z or 3x3 + 2x2 + x.

  2. Biology. a trinomial name, as Rosa gallica pumila.

Origin of trinomial

First recorded in 1665–75; tri- + (bi)nomial

Other words from trinomial

  • tri·no·mi·al·ly, adverb

Words Nearby trinomial Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use trinomial in a sentence

British Dictionary definitions for trinomial


/ (traɪˈnəʊmɪəl) /

  1. maths consisting of or relating to three terms

  2. biology denoting or relating to the three-part name of an organism that incorporates its genus, species, and subspecies

  1. maths a polynomial consisting of three terms, such as ax ² + bx + c

  2. biology the third word in the trinomial name of an organism, which distinguishes between subspecies

Origin of trinomial

C18: tri- + -nomial on the model of binomial

Derived forms of trinomial

  • trinomially, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for trinomial


[ trī-nōmē-əl ]

  1. A mathematical expression that is the sum of three monomials, such as ax2 + bx - c.

  2. A taxonomic designation indicating genus, species, and subspecies or variety, as in Brassica oleracea botrytis, the cauliflower.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.