what is the meaning of binomial

http://www.m-w.com/cgi-bin/dictionary

two names

It is used to identify plants

You can look it up in an online dictionary. I did.

Main Entry: bi·no·mi·al
Pronunciation: bI-'nO-mE-&l
Function: noun
Etymology: New Latin binomium, from Medieval Latin, neuter of binomius having two names, alteration of Latin binominis, from bi- + nomin-, nomen name —more at NAME
Date: 1557
1 : a mathematical expression consisting of two terms connected by a plus sign or minus sign
2 : a biological species name consisting of two terms
- binomial adjective
- bi·no·mi·al·ly /-mE-&-lE/ adverb

I hope this helps a little more. Thanks for asking.