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Words with the prefix bi-

bi- means “two; twice”, from Latin.

15 examples of the prefix bi-

  1. bicyclebi- + cycletwo-wheeled riding vehicle
  2. bilingualbi- + lingualspeaking two languages
  3. biweeklybi- + weeklyevery two weeks
  4. bifocalbi- + focalhaving two focal points
  5. bimonthlybi- + monthlyevery two months
  6. biannualbi- + annualoccurring twice a year
  7. bilateralbi- + lateralinvolving two sides
  8. bipartisanbi- + partisaninvolving two political parties
  9. bisectbi- + sectcut into two equal parts
  10. biennialbi- + ennialoccurring every two years
  11. bicameralbi- + cameralhaving two legislative chambers
  12. bipolarbi- + polarhaving two opposite poles
  13. binomialbi- + nomialexpression with two terms
  14. biculturalbi- + culturalrelating to two cultures
  15. bifurcatebi- + furcatedivide into two branches

How bi- works

The prefix 'bi-' attaches to nouns and adjectives to form adjectives or nouns meaning 'two' or 'twice,' and occasionally to verbs (as in 'bisect'). It does not undergo spelling assimilation the way prefixes like 'in-' do, remaining uniformly 'bi-' before all base words.

Watch out: Words like 'bite,' 'bird,' 'bill,' and 'big' look as if they begin with 'bi-' but the letters are simply part of the root with no connection to the prefix meaning 'two.'

To see prefixes combine with other parts, try the word dissector and root builder, or test yourself in the vocabulary quiz.

Other common prefixes

Questions people ask

What does the prefix bi- mean?

bi- means “two; twice”. It comes from Latin. The prefix 'bi-' attaches to nouns and adjectives to form adjectives or nouns meaning 'two' or 'twice,' and occasionally to verbs (as in 'bisect'). It does not undergo spelling assimilation the way prefixes like 'in-' do, remaining uniformly 'bi-' before all base words.

What are some examples of words with the prefix bi-?

bicycle, bilingual, biweekly, bifocal, bimonthly, biannual, bilateral, bipartisan. The full list of 15 examples, with what each one literally means, is above.

Which words look like they have the prefix bi- but don’t?

Words like 'bite,' 'bird,' 'bill,' and 'big' look as if they begin with 'bi-' but the letters are simply part of the root with no connection to the prefix meaning 'two.'

What is a prefix?

A prefix is a word part added to the front of a base word or root to change its meaning, like un- in unhappy or re- in rewrite. It does not usually change the part of speech.