- (physics) Involving quanta.
- (informal) Of a change, significant.
- Of a change, sudden or discrete, without intermediate stages.
- (computing theory) Relating to a quantum computer.
- (mathematics) A definite portion of a manifoldness, limited by a mark or by a boundary.
- (physics) The smallest possible, and therefore indivisible, unit of a given quantity or quantifiable phenomenon. [from 20th c.]
- The amount or quantity observably present, or available. [from 18th c.]
- (now chiefly South Asia) The total amount of something; quantity. [from 17th c.]