- Prefix meaning two, as in biceps or bicuspid.
* * *1. Prefix meaning twice or double, referring to double structures or dual actions. 2. In chemistry, used to denote a partially neutralized acid (an acid salt); e.g., bisulfate. Cf.:bis-, di-. [L.]
* * *prefix denoting
* * *[L. bi-, from bis twice] a prefix meaning two, twice, or double. In chemistry, it denotes the presence of a component in twice the proportion of the other component or in twice the usual proportion, or a double radical, except that in bicarbonate, bisulfate, and bitartrate, the prefix di- is preferred. Before vowels it appears as bin-.
Medical dictionary. 2011.