bi-

¹

1. a combining form meaning “twice,” “two,” used in the formation of compound words.

   bifacial; bifarious.

bi-

²

1. variant of bio-, especially before a vowel.

   biopsy.

bi

³

[bahy]

adjective

plural

bis, bi's 

1. Slang.,  bisexual.

Bi

⁴

Symbol, Chemistry.

1. bismuth.

BI

⁵

abbreviation

plural

BI's 

1. built-in.

2. business intelligence.

bi-

¹

combining form

1. two; having two

   bifocal

2. occurring every two; lasting for two

   biennial

3. on both sides, surfaces, directions, etc

   bilateral

4. occurring twice during

   biweekly

5. 1. denoting an organic compound containing two identical cyclic hydrocarbon systems

      biphenyl

   2. (rare in technical usage) indicating an acid salt of a dibasic acid

      sodium bicarbonate

   3. (not in technical usage) equivalent of di- 1

Bi

²

symbol

1. bismuth

bi

³

/ baɪ /

adjective

1. slang,  short for bisexual bisexual

bi-

⁴

combining form

1. a variant of bio-

bi

⁵

abbreviation

1. Burundi

Confusables Note

All words except biennial referring to periods of time and prefixed by bi- ¹ are potentially ambiguous. Since bi- can be taken to mean either “twice each” or “every two,” a word like biweekly can be understood as “twice each week” or “every two weeks.” To avoid confusion, it is better to use the prefix semi- to mean “twice each” ( semiannual; semimonthly; semiweekly ) or the phrase twice a or twice each ( twice a month; twice a week; twice each year ), and for the other sense to use the phrase every two ( every two months; every two weeks; every two years ).

Word History and Origins

Origin of bi-¹

< Latin, combining form of bis; twice

Origin of bi-²

By shortening

Word History and Origins

Origin of bi-¹

from Latin, from bis _twice

Example Sentences

In “The Rat Race,” she flirts with a chatty restaurant server making tableside guacamole, who, like her, hate-watches a reality show called “Bi Bingo.”

From Salon

"When you lock things up, for example, you don't sell as many of them," BI reported.

From Salon

Other retailers are testing ways to prevent shoplifting, BI reported.

From Salon

“We were talking about doing something bicultural, bilingual, bi la, la, la,” Romero, 83, says.

From Los Angeles Times

One of the men, Theodore Bi, called the work “an idea anyone can get behind” and said they had intended to give it as a gift to Elon Musk.

From New York Times

When To Use

What does bi- mean?

Bi- is a combining form used like a prefix, and it means “two” or “twice.” It is often used in scientific terms, but it crops up in everyday language as well.Bi- comes from Latin bis, meaning “twice, doubly.” The Greek equivalent of this combining form is di-, as in diacid.What are variants of bi-?Bi- is related to the combining form bin- and is used with some words or word elements beginning with vowels. These two forms have similar origins, and for that reason, the difference between the two is a small yet important nuance: bi- often means “twice,” while bin- typically means “double.”Want to know more? Read our Words That Use bin- article.