theorem

/ˈθiː.ə.ɹəm/

Proposed by a contributor, not yet supported by evidence.

Also seen as: theorems · theoreming · theoremed

Sense 1

Meaning · English

A mathematical statement of some importance that has been proven to be true. Minor theorems are often called propositions. Theorems which are not very interesting in themselves but are an essential part of a bigger theorem's proof are called lemmas.

Noun

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 2

Meaning · English

A mathematical statement that is expected to be true.

NounRegister: colloquial

Examples

Fermat's Last Theorem was known thus long before it was proved in the 1990s.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 3

Meaning · English

To formulate into a theorem.

Verb

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Common questions

What does “theorem” mean?

A mathematical statement of some importance that has been proven to be true. Minor theorems are often called propositions. Theorems which are not very interesting in themselves but are an essential part of a bigger theorem's proof are called lemmas.

Is “theorem” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.