bi-
Prefix meaning double
Bi- is a prefix meaning two or twice: bicycle, biannual, bilingual, bisexual.
It attaches to nouns and adjectives to indicate duality or double occurrence.
Biweekly and bimonthly are notoriously ambiguous—they can mean either twice per week/month or every two weeks/months, so context or clarification is often needed.
Involving two parties
- bifurcateDivide into two branches
- bipartisanInvolving both major parties
- binaryConsisting of two parts
- bilingualSpeaking two languages
bicameral · biannual · biweekly · bifocal · bicycle · binocular · bipolar · bisect
All life on Earth
- biodiversityRange of life forms
- biorhythmInnate physiological cycle
- biomeMajor ecological community
- biopsyTissue sample for diagnosis
biomass · biogenesis · biofeedback · biosynthesis · biotechnology · biomarker · biofilm · bioreactor
bilateral
Involving two parties
- bifurcateDivide into two branches
- bipartisanInvolving both major parties
- binaryConsisting of two parts
bilingual · bicameral · biannual · biweekly · bifocal · bicycle · binocular · bipolar · bisect · bivalve
biosphere
All life on Earth
- biodiversityRange of life forms
- biorhythmInnate physiological cycle
- biomeMajor ecological community
biopsy · biomass · biogenesis · biofeedback · biosynthesis · biotechnology · biomarker · biofilm · bioreactor · biodegradable
bisexual
Attracted to multiple genders
- biphobiaPrejudice against bisexual people
bicarbonate
Acid-neutralizing salt
bismuth · biotin · biopolymer