the.com/biweekly
The word that means two opposite things and apologizes for neither.
means Either every two weeks or twice a week, and context rarely tells you which.
from From Latin bi- (two) glued to weekly — a prefix that fatally forgot whether two means times or divided by.
Evil twinBimonthly shares the exact same ambiguity curse.
Payroll chaosBiweekly pay means 26 checks, not 24.
Editor's fixStyle guides beg you to write fortnightly instead.