Infinity
Etymology
From Latin “infinitas” (boundlessness), from in- (not) plus finis (end, boundary). The symbol ∞ was introduced by the English mathematician John Wallis in 1655, and later work by Georg Cantor showed, startlingly, that some infinities are larger than others.
noun · /in-FIN-ih-tee/
The idea of a quantity without any end or bound — larger than any number you can name.
What it names
It marks the boundary of the countable and forces a distinction between “very large” and “endless” that everyday talk erases.
Example
Saying a process “could take infinitely long” is a real claim, not a figure of speech for “a very long time.”
Related idea
Infinity is a limit, not a number, which is why an asymptote approaches it without reaching it; treating infinity as an ordinary quantity — dividing by it, say — is a classic source of paradox.