What does bimestrial mean?
Bimestrial is a relatively rare adjective describing something that occurs every two months or that lasts for a period of two months. It is built on the same pattern as words like biennial and biannual, combining the Latin prefix bi- ('two') with mensis ('month'), and serves as a more precise alternative to bimonthly, a term notorious for its ambiguity since it can mean either twice a month or once every two months. Bimestrial appears mainly in formal registers — academic publishing, administrative scheduling, and organizational timetables — as in 'a bimestrial newsletter' or 'bimestrial reviews'. Because the word is unfamiliar to many readers, writers who use it should be confident their audience will understand, or should simply state the interval explicitly. Its chief value lies in removing doubt about frequency, making it useful wherever precision about a two-month cycle matters.
adjectiveOccurring every two months, or lasting for a period of two months. In some contexts it is used interchangeably with 'bimonthly', which can itself mean either twice a month or once every two months.
- Occurring every two months.
- Lasting or extending over a period of two months.
"The society holds bimestrial meetings to review its grant applications."
"The journal moved from quarterly to a bimestrial publishing schedule in order to keep pace with new research."
"The committee's bimestrial review meant that no application waited longer than sixty days for a decision."
When 'bimonthly' became too ambiguous — does it mean twice a month or every two months? — English borrowed this precise Latin-built alternative.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bimestrial
Bimestrial derives from the Latin bimestris, meaning 'of two months', formed from bi- ('two') and mensis ('month') — the same root that gives us menstrual and semester via related Romance developments. The word entered English through post-classical and scientific Latin usage, following the productive pattern of other Latinate frequency adjectives such as biennial ('every two years'). It remains far less common than its rival bimonthly, but shares the family of precise temporal terms English has borrowed to disambiguate periodic events.
How bimestrial is actually used
A formal word, found chiefly in academic, administrative, and publishing contexts. It is considerably rarer than 'bimonthly', whose ambiguity it avoids, but many readers may be unfamiliar with it, so clarity sometimes favors spelling out the interval instead.
Easily confused with bimestrial
'Bimonthly' can ambiguously mean either twice a month or once every two months, whereas 'bimestrial' unambiguously refers to something occurring every two months or spanning a two-month period.
'Biennial' means occurring every two years, while 'bimestrial' operates on a scale of months rather than years.