theorem

noun

the·​o·​rem ˈthē-ə-rəm 

ˈthir-əm

1

: a formula, proposition, or statement in mathematics or logic deduced or to be deduced from other formulas or propositions

2

: an idea accepted or proposed as a demonstrable truth often as a part of a general theory : proposition

the theorem that the best defense is offense

3

: stencil

4

: a painting produced especially on velvet by the use of stencils for each color

theorematic

ˌthē-ə-rə-ˈma-tik 

ˌthir-ə-

adjective

Examples of theorem in a Sentence

Recent Examples on the Web

In the mid-Aughts, armed with the theorem, the rationalists discovered that humanity is in jeopardy of a rogue superintelligent AI wiping out all life on the planet. —Sam Kriss, Harpers Magazine, 24 Feb. 2026

But Mordell’s conjecture, now called Faltings’s theorem, says nothing about how many points these curves have. —Joseph Howlett, Scientific American, 24 Feb. 2026

This is an existence theorem, not a construction manual. —Amir Husain, Forbes.com, 29 Jan. 2026

There have been previous attempts to bypass the no-cloning theorem, says Yamaguchi. —IEEE Spectrum, 25 Jan. 2026

Word History

Etymology

Late Latin theorema, from Greek theōrēma, from theōrein to look at, from theōros spectator, from thea act of seeing — more at theater entry 1

First Known Use

1551, in the meaning defined at sense 1

Phrases Containing theorem

• Bayes's theorem
• Bayes theorem
• binomial theorem
• central limit theorem
• DeMoivre's theorem
• Fermat's last theorem
• Fourier's theorem
• Godel's theorem
• Jordan curve theorem
• mean value theorem
• Pythagorean theorem
• remainder theorem
• Rolle's theorem

Rhymes for theorem

• variorum
• antiserum
• serum
• thiram

Kids Definition

theorem

noun

the·​o·​rem ˈthē-ə-rəm 

ˈthi(-ə)r-əm

1

: a formula, proposition, or statement in mathematics or logic that has been or is to be proved from other formulas or propositions

2

: an idea accepted or proposed as a demonstrable truth