- noun an amount, especially a large amount
- noun the amount or number of items
- A specified number, amount, or value.
- A large number, amount, or value.
- For a given component, circuit, device, system, material, or the like, a property which is measurable, countable, or can otherwise be expressed as a quantity (1).
- An entity which has a value or magnitude, upon which mathematical operations may be performed.
Origin & History of “quantity”
Latin quantus meant ‘how much’ (it was a compound adjective formed from quī ‘who’). From it was derived the noun quantitās ‘extent, amount’, which passed into English via Old French quantite. Quantum (17th c.), a noun use of the neuter form of the Latin adjective, originally denoted simply ‘amount’; its specific application to a ‘minimum amount of matter’ was introduced by Max Planck in 1900, and reinforced by Einstein in 1905.