Adjacent Words

bi- definitions

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Merriam Webster's

I. prefix Etymology: Middle English, from Latin — more at twi- 1. a. two <bilateral> b. coming or occurring every two <bicentennial> c. into two parts <bisect> 2. a. twice ; doubly ; on both sides <biconvex> b. coming or occurring two times <biannual> — compare semi- 3. between, involving, or affecting two (specified) symmetrical parts <bilabial> 4. a. containing one (specified) constituent in double the proportion of the other constituent or in double the ordinary proportion <bicarbonate> b. di- 2 <biphenyl> Usage: Many people are puzzled about bimonthly and biweekly, which are often ambiguous because they are formed from both senses 1b and 2b of bi-. This ambiguity has been in existence for nearly a century and a half and cannot be eliminated by the dictionary. The chief difficulty is that many users of these words assume that others know exactly what they mean, and they do not bother to make their context clear. So if you need bimonthly or biweekly, you should leave some clues in your context to the sense of bi- you mean. And if you need the meaning “twice a,” you can substitute semi- for bi-. Biannual and biennial are usually differentiated. II. combining form or bio- Etymology: Greek, from bios mode of life — more at quick 1. life ; living organisms or tissue <bioluminescence> <biosphere> 2. biographical <biopic>

Oxford Reference Dictionary

comb. form (often bin- before a vowel) forming nouns and adjectives meaning: 1 having two; a thing having two (bilateral; binaural; biplane). 2 a occurring twice in every one or once in every two (bi-weekly). b lasting for two (biennial). 3 doubly; in two ways (biconcave). 4 Chem. a substance having a double proportion of the acid etc. indicated by the simple word (bicarbonate). 5 Bot. & Zool. (of division and subdivision) twice over (bipinnate). Etymology: L

Webster's 1913 Dictionary

Bi- Bi- [L. bis twice, which in composition drops the -s, akin to E. two. See Bis-, Two, and cf. Di-, Dis-.] 1. In most branches of science bi- in composition denotes two, twice, or doubly; as, bidentate, two-toothed; biternate, doubly ternate, etc. 2. (Chem.) In the composition of chemical names bi- denotes two atoms, parts, or equivalents of that constituent to the name of which it is prefixed, to one of the other component, or that such constituent is present in double the ordinary proportion; as, bichromate, bisulphide. Be- and di- are often used interchangeably.

Collin's Cobuild Dictionary

1. Bi- is used at the beginning of nouns and adjectives that have 'two' as part of their meaning. ...a bi-cultural society. PREFIX 2. Bi- is used to form adjectives and adverbs indicating that something happens twice in a period of time or happens once in two periods of time that follow each other. Students meet biweekly to discuss their experiences. ...a bimonthly magazine. PREFIX