the GNU version of the Collaborative International Dictionary of English
adj. Continuing two months.
The Century Dictionary and Cyclopedia
Happening every two months; continuing two months.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. occurring every two months
adj. two months long; lasting two months
Word Usage
"(June, 1300), -- an office which the Florentines had made bimestrial in its tenure, in order apparently to secure at least six constitutional chances of revolution in the year."