[ bʌɪ ]
(also bin- before a vowel)
■ combining form two; having two: biathlon.
↘occurring twice in every one or once in every two: bicentennial.
↘lasting for two: biennial.
↘ Chemistry (in names of compounds) containing two atoms or groups of a specified kind: biphenyl.
↘ Chemistry denoting an acid salt: bicarbonate.
Origin
from L., 'doubly, having two'; related to Gk di- 'two'.
Usage
The meaning of bimonthly (and similar words such as biyearly ) is ambiguous. Such words can either mean ‘occurring or produced twice a month’ or ‘occurring or produced every two months’. The only way to avoid this ambiguity is to use alternative expressions like every two months and twice a month .