“Generally, bi- means two (biweekly means every two weeks), while semi- means half (semiweekly means twice a week).
A Word, Please: Does bimonthly mean twice a month or every two months?
www.latimes.com > socal > daily-pilot > opinion > story > a-word-please-d...
Use the b in biweekly to remind you that the word means both 'twice a week' and 'every two weeks'. Use the for in fortnight to remind that the word means 'every fourteen days'.
Commonly Confused Words: Biweekly vs. Fortnightly vs. Semi-weekly
www.spellzone.com > blog > Commonly_Confused_Words_Biweekly_vs_...
Biweekly and bimonthly can mean the same thing because of the prefix bi-, which here can mean “occurring every two” or “occurring twice in.” Therefore, biweekly can be “twice in a week” or “every other week.” Bimonthly can also mean "every other week" if it's twice in a month, or it can mean “every other month.”
On 'Biweekly' and 'Bimonthly' - Merriam-Webster
www.merriam-webster.com > words-at-play > on-biweekly-and-bimonthly
(Entry 1 of 2) 1 : occurring every two weeks : fortnightly. 2 : occurring twice a week.
Definition of Biweekly by Merriam-Webster
www.merriam-webster.com > dictionary > biweekly