occurring every two months.
occurring twice a month; semimonthly.

noun, plural bi·month·lies.

a bimonthly publication.


every two months: Next year we plan six field trips to take place bimonthly.
twice a month; semimonthly.

Origin of bimonthly

First recorded in 1840–50; bi-1 + monthly
Can be confusedbimonthly biweekly semimonthly (see usage note at bi-1)

Usage note

See bi-1. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for bimonthly

Contemporary Examples of bimonthly

Historical Examples of bimonthly

British Dictionary definitions for bimonthly


adjective, adverb

every two months
(often avoided because of confusion with sense 1) twice a month; semimonthlySee bi- 1

noun plural -lies

a periodical published every two months
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for bimonthly

also bi-monthly, 1846, "happening once in two months, every two months," also "occurring twice a month," a hybrid from bi- + monthly.

Online Etymology Dictionary, © 2010 Douglas Harper