Where does “bimonthly” come from?

I need to work through this chain carefully, but I notice some issues: the chain shows "Latin duo" twice and ends with "Proto-Indo-European ḱóm" which doesn't connect logically to "duo" (meaning "two"). The chain also seems incomplete for explaining "bimonthly." However, following the rule to "state only what the chain supports" and not invent steps, I cannot write an accurate sentence because the etymological chain provided doesn't establish a clear path to "bimonthly." Could you verify the chain? A proper etymology for "bimonthly" should trace through: - English bimonthly - English bi- (prefix meaning "two") - Latin bi- or duo (two) - etc. But the chain you've provided seems to conflate "monthly" with "bimonthly" and includes elements that don't connect clearly. Would you

bimonthly (English): Occurring once every two months; bimestrial;...