Binomial

1. a. Having two names; — used of the system by which every animal and plant receives two names, the one indicating the genus, the other the species, to which it belongs.
2. n. An expression consisting of two terms connected by the sign plus (+) or minus (-); as, a + b, or 7 – 3.
3. a. Consisting of two terms; pertaining to binomials; as, a binomial root.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.