Webster's Revised Unabridged Dictionary · 1913

Theorem

Theorem , noun

[Latin theorema, Greek {not transcribed} a sight, speculation, theory, theorem, from {not transcribed} to look at, {not transcribed} a spectator: compare French théorème. See Theory.]

1.
That which is considered and established as a principle; hence, sometimes, a rule.
Not theories, but theorems ({not transcribed}), the intelligible products of contemplation, intellectual objects in the mind, and of and for the mind exclusively. — Coleridge
By the theorems, Which your polite and terser gallants practice, I re-refine the court, and civilize Their barbarous natures. — Massinger
2.
(Mathematics) A statement of a principle to be demonstrated.

A theorem is something to be proved, and is thus distinguished from a problem, which is something to be solved. In analysis, the term is sometimes applied to a rule, especially a rule or statement of relations expressed in a formula or by symbols; as, the binomial theorem; Taylor's theorem. See the Note under Proposition, n., 5.

Collocations (5)
Binomial theorem (Mathematics) , See under Binomial.
Negative theorem , a theorem which expresses the impossibility of any assertion.
Particular theorem (Mathematics) , a theorem which extends only to a particular quantity.
Theorem of Pappus (Mathematics) , See Centrobaric method, under Centrobaric.
Universal theorem (Mathematics) , a theorem which extends to any quantity without restriction.

Theorem , transitive verb

To formulate into a theorem.