trinomial noun & adjective. [trʌɪ'nǝʊmɪǝl] L17.
[from TRI- after BINOMIAL.]
A. noun.
1. Math. An expression consisting of three terms connected by plus or minus signs. L17.

2. Biology. A trinomial taxonomic name. L19.
b. adjective.
1. Math. Consisting of three terms. E18.

2. Biology. Of a scientific name: consisting of three terms, esp. where the first is the name of the genus, the second that of the species, the third that of the subspecies or variety. Also, involving or characterized by such names. M19.

3. Of a married woman's name, esp. in the US: consisting of three elements, the forename, maiden name, and husband's surname. Of a woman: having such a name. M20.

■ trinomialism noun the trinomial system of nomenclature, the use of trinomial names L19.

■ trinomially adverb by the use of trinomial names L19.

[TahlilGaran] English Dictionary ▲