- quantum - a discrete amount of something that is analogous to the quantum in quantum theory
--1 is a kind of quantity
- quantum - (physics) the smallest discrete quantity of some physical property that a system can possess (according to quantum theory)
--2 is a kind of measure, quantity, amount
--2 has particulars: quasiparticle - quantum - (physics) the smallest discrete quantity of some physical property that a system can possess (according to quantum theory)