Multiply Definition & Meaning - Merriam-Webster
Definition of multiply. (Entry 1 of 3) transitive verb. 1 : to increase in number especially greatly or in multiples
And again,
transitive verb
1a : to become greater in number :
That there are other definitions as well doesn’t negate the fact that it also means to increase in number— -
“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.
Look up "homonym" while you're at it.
p.s. If 5 x 0 = 0, which number got increased, the 0 or the 5?