“That there are other definitions as well doesn’t negate the fact that it also means to increase in number— -”
It means that in a literary context, if you are writing prose or poetry. It definitely does not mean that in a mathematical context, which is the only context that matters when we are discussing mathematics.
[[It definitely does not mean that in a mathematical context,]]
“The basic words of math like “multiply” and “add” were adapted from everyday life long ago. Back then, concepts like negative numbers and even zero had not been developed. People would really only think in terms of multiplying by positive whole numbers. And why bother to multiply by 1? It doesn’t do anything. So the use of the words made sense.
But mathematicians gradually extended the meanings of the words. Not only can you multiply fractions or negative numbers, you can multiply matrices or numbers in modular arithmetic, where the idea of one number being greater than another is meaningless.
The basic words of math like “multiply” and “add” were adapted from everyday life long ago. Back then, concepts like negative numbers and even zero had not been developed. People would really only think in terms of multiplying by positive whole numbers.”
https://www.themathdoctors.org/how-can-multiplication-make-it-smaller/
Multiply in math does means increase- it now also can mean decrease- As mentioned, just because a word has expanded and now has other meanings, that fact does not mean that it negates the original meaning- the original meaning of multiply applies to math as well- folks multiplied numbers and got increases before learning about fractions and negative numbers