Here is a bit of explanation so that you can see where I am going with this piece of wisdom in which you may have absolutely no interest.
The letters “in” at the beginning of a word usually indicate the negative (not), such as inept, inconsistent, or inappropriate. However, with the English language being quite confusing, to say the least, words like inflame or inflamed do not follow this rule because the “in” is treated more like “en” in this context. Thus “inflame” means “to heat up” in terms of emotions, and “irritated” or “infected” in term of bodily organs; nothing to do with catching fire or bursting into flames.
Now, for where I’m going. Some time ago, the word “inflammable” was used to describe something that would burn easily. However, the prefix “in” suggested it could mean “not flammable.” To eliminate this apparent ambiguity, the word was changed to “flammable” (could burn).
That change seems to have worked out well.
It is not the same however, with the prefix “bi” which could mean either of two things, one being the opposite of the other. The term “bi-monthly” for a publication could mean either every two months or twice a month. The same is true for bi-weekly publications. Bi-annual publications may be published every two years or semi-annually.
Check it out yourself on whatever search engine you prefer.