- (countable) A quantum is the smallest amount of a physical quantity that can exist independently.
- Energy is transferred in small packets called quanta.
- (usually before a noun) Quantum physics/computing/mechanics, etc. is related to quanta in sense 1.
- Particles like electrons behave differently at the quantum level.
- (usually before a noun) A quantum change is a very large one.
- There has been a quantum shift in the way people think about this.
- (usually before a noun) A quantum change is one that is sudden and non-continuous, moving from one state another without any intermediate states.
- A quantum leap occurs abruptly, without gradual transition.
- (countable) (law) The quantum of something is its total amount.
- The court decided the quantum of damages to be paid.
