Quantum

How to spell quantum

7 letters · 2 syllables

How to pronounce quantum

Say the part in capitals loudest.

What does quantum mean?

1. nounThe smallest discrete amount of a physical quantity, such as energy, that can exist independently.
2. nounA specified quantity, share, or portion of something, often used in legal or formal contexts.

Quantum in a sentence

• The lecture explained how a single quantum of light is called a photon.

• The court still has to decide the quantum of damages owed to the claimant.

• Energy is released in each tiny quantum rather than in a smooth flow.

• Lawyers argued over the precise quantum of compensation for the injury.

Where does quantum come from?

Language of origin: Latin

Quantum comes directly from Latin, where it is the neuter form of quantus, an adjective meaning 'how much' or 'how great'. In Latin the word literally answered the question of size or quantity, and English borrowed it in the 1600s to mean simply 'an amount' or 'a portion', a sense still used in legal and financial writing today. Its modern fame arrived in the early twentieth century, when the physicist Max Planck used the Latin term to name the smallest discrete packet into which energy could be divided, giving us quantum physics. The same root sits inside everyday English words such as 'quantity' and 'quantify', which is a useful reminder that the spelling keeps the Latin -um ending rather than the more English-looking -om. Because the word is taken straight from Latin with no change of form, its spelling has stayed remarkably stable across the centuries.

How the word is built

• quant- (from Latin quantus: how much, how great)
• -um (Latin neuter noun ending)