Origin: L bi- < OL dui- < IE *dwi- < base *dwo-, two
See bi in American Heritage Dictionary 4
noun pl. bis or bi's
Origin: Latin bis, bi-, twice,
Origin: and bīnī, two by two; see dwo- in Indo-European roots. Usage Note: Bimonthly and biweekly mean “once every two months” and “once every two weeks.” For “twice a month” and “twice a week,” the words semimonthly and semiweekly should be used. Since there is a great deal of confusion over the distinction, a writer is well advised to substitute expressions like every two months or twice a month where possible. However, each noun form has only one sense in the publishing world. Thus, a bimonthly is published every two months, and a biweekly every two weeks.
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