One hill I will die on: bi-weekly should only ever mean twice a week. Semi-weekly (or fortnightly) is for once every two weeks.

I will mute everyone who disagrees and pretend they never existed

PhD in aviation ∩ climate science | Aviator, diver, ETH maxi, nexialist | Host of /diving /ethfinance /eth-staker /geopolitics /science /singapore /thomas

I feel like this is a uniquely American term, but is it ambiguous to anyone? For me, it's just an adjective applying to any object (e.g., an area) that involves three different states

If your question is specifically about tri-, I see no confusion there, but then again I studied Latin and my native language is a Romance one, so bi-, tri-, quadri-, etc. are natural prefixes for me