Definition of bi- in English:


Translate bi- into Spanish

(also bin-)
  • 1Two; having two.

    • ‘bicolored’
    • ‘binocular’
    1. 1.1Occurring twice in every one.
      • ‘bimonthly’
    2. 1.2Occurring once in every two.
      • ‘biennial’
    3. 1.3Lasting for two.
      • ‘biennium’
    4. 1.4Doubly; in two ways.
      • ‘biconcave’
    5. 1.5Chemistry A substance having a double proportion of the radical, group, etc., indicated by the simple word.
      • ‘binoxalate’
    6. 1.6Botany Zoology (of division and subdivision) twice over.
      • ‘bipinnate’



/bī/ /baɪ/


The meaning of bimonthly (and other similar words such as biweekly and biyearly) is ambiguous. Bimonthly, for instance, can mean either ‘occurring or produced twice a month’ or ‘occurring or produced every two months.’ So, if an organization holds bimonthly meetings, over the course of a year, will it meet six times or twenty-four times? The only way to avoid this ambiguity is to use alternative expressions like every two months and twice a month. See also biennial


From Latin, ‘doubly, having two’; related to Greek di- ‘two’.