What does bi mean?
'Bi' is an informal shortening of 'bisexual', used as a noun to describe a person who experiences attraction to more than one gender. It emerged as casual shorthand within LGBTQ+ communities and has become widely recognized in everyday speech, journalism, and popular culture. The term carries a neutral-to-positive connotation today, though attitudes toward bisexuality have historically included misunderstanding, giving rise to concepts like 'bi erasure'. Beyond its use as a standalone word, 'bi-' functions as a productive combining form from Latin, meaning 'two', 'twice', or 'both', appearing in words such as 'bicycle', 'bilingual', and 'bipartisan'. Because of its brevity, 'bi' is easily confused in speech with 'by' and 'buy', though context almost always disambiguates. Whether describing identity or doubling a quantity, this tiny word carries substantial weight.
An informal term for a bisexual person: someone attracted to people of more than one gender.
"Several cast members openly identify as bi."
Informal register; widely accepted but 'bisexual' may be preferred in formal contexts.
A combining form meaning 'two', 'twice', or 'both', from Latin, as in bicycle, bilingual, or bipartisan.
"The word 'biannual' can mean twice a year or every two years — a notorious ambiguity."
Rarely needed; when referring to multiple bisexual people, plural phrasing like 'bi people' is more common than the plural noun form.
"The panel featured several bis sharing their coming-out stories."
The same two-letter word that gave us 'bicycle' and 'bilingual' now stands proudly on millions of Pride flags around the world.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bi
As a standalone word, 'bi' arose in the 20th century as a clipped, colloquial form of 'bisexual', which itself combines the Latin prefix 'bi-' ('two') with 'sexual'. The prefix traces back to Latin 'bis', meaning 'twice', related to 'duo' ('two'), and entered English through learned borrowings such as 'bicycle' and 'bilingual'. Its modern identity-related sense reflects both this ancient root of duality and contemporary usage within LGBTQ+ communities.
Related word forms
How bi is actually used
As a standalone noun, 'bi' is informal but widely accepted within LGBTQ+ communities and mainstream media; some prefer the fuller term 'bisexual' in formal writing. The combining form 'bi-' remains productive in technical and everyday vocabulary.
Easily confused with bi
'By' is a preposition or adverb indicating agency or location, while 'bi' is an informal noun for a bisexual person.
'Buy' means to purchase something, whereas 'bi' informally denotes a bisexual person.