bi-

bi-

bi-¹ [bī]

[L bi- < OL dui- < IE * dwi- < base * dwo-, TWO] prefix

1. having two [biangular, bicapsular]

2. doubly, on both sides, in two ways or directions [biconvex, bilingual]

3. coming, happening, or issued every two (specified periods) [biennial, biweekly]

4. coming, happening, or issued twice during every (specified period): often replaced by SEMI- or half-, to avoid confusion with preceding sense [bimonthly, biyearly]

5. using two or both [bilabial, bimanual]

6. joining two, combining or involving two [bilateral, bipartisan]

7. Bot. Zool. twice, doubly, in pairs [bifurcate, bipinnate]

8. Chem.

a) having twice as many atoms or chemical equivalents for a definite weight of the other constituent of the compound [sodium bicarbonate]

b) in organic compounds, having a combination of two radicals of the same composition [biphenyl]: usually replaced by DI-¹ (sense 2) except in the names of acid salts [ potassium bitartrate]: It becomes bin- before a vowel and bis- before c or s

bi-² [bī]

combining form

BIO-