tri·​no·​mi·​al | \ trī-ˈnō-mē-əl How to pronounce trinomial (audio) \

Definition of trinomial

 (Entry 1 of 2)

1 : a polynomial of three terms
2 : a biological taxonomic name of three terms of which the first designates the genus, the second the species, and the third the subspecies or variety



Definition of trinomial (Entry 2 of 2)

1 : consisting of three mathematical terms
2 : of, relating to, or being a biological trinomial

Examples of trinomial in a Sentence

Recent Examples on the Web: Noun How necessary is intermediate algebra, a high school-level course on factoring trinomials, graphing exponential functions and memorizing formulas that most non-math or science students will rarely use in everyday life or for the rest of college? Rosanna Xia,, "The politics of math: Is algebra necessary to obtain a college degree?," 30 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'trinomial.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of trinomial


1674, in the meaning defined at sense 1


circa 1704, in the meaning defined at sense 1

History and Etymology for trinomial


tri- + -nomial (as in binomial)

Keep scrolling for more

Learn More about trinomial

Time Traveler for trinomial

Time Traveler

The first known use of trinomial was in 1674

See more words from the same year

Statistics for trinomial

Cite this Entry

“Trinomial.” Dictionary, Merriam-Webster, Accessed 2 Dec. 2020.

Keep scrolling for more

More Definitions for trinomial


tri·​no·​mi·​al | \ trī-ˈnō-mē-əl How to pronounce trinomial (audio) \

Medical Definition of trinomial

 (Entry 1 of 2)

: a trinomial name



Medical Definition of trinomial (Entry 2 of 2)

1 : being a name belonging to botanical or zoological nomenclature composed of a first term designating the genus, a second term designating the species, and a third term designating the subspecies or variety to which an organism belongs
2 : of or relating to trinomials trinomial nomenclature

Comments on trinomial

What made you want to look up trinomial? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Musical Words Quiz

  • gramophone
  • Which word describes a musical performance marked by the absence of instrumental accompaniment?
Spell It

Can you spell these 10 commonly misspelled words?

Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!