I am not sure whether this belongs here, or in the mangled maths thread, but "quantum" seems to be a Latin word that has both moved beyond its original Latin meaning, and gets seriously mangled in everyday use. Given that its accepted definition in physics is something like:
"1.The smallest amount of a physical quantity that can exist independently, especially a discrete quantity of electromagnetic radiation.
2. This amount of energy regarded as a unit. "

I am always amused when I hear of a quantum leap being made in some field of human endeavour

Even in a more general definition:
"1.A quantity or an amount.
2. A specified portion.
3. Something that can be counted or measured."

it appears to fit the description of a purely Latin word (one that would be recognised as such by a native Latin speaker) which has moved beyond its Latin meaning.