theorize

verb

the·​o·​rize ˈthē-ə-ˌrīz 

ˈthir-ˌīz

theorized; theorizing

intransitive verb

: to form a theory : speculate

transitive verb

1

: to form a theory about

2

: to propose as a theory

theorization

ˌthē-ə-rə-ˈzā-shən 

ˌthir-ə-

noun

theorizer noun

Examples of theorize in a Sentence

Many scientists have theorized about the possibility of life on other planets.

Recent Examples on the Web

Some analysts have theorized that Apple’s most committed fans may have been waiting to see the Duo come out before buying it. — Kif Leswing, CNBC, 2 Nov. 2026

Researchers theorize the pigment allows the fish to spot bioluminescence, giving it an additional tool to maneuver through the murky depths. — Andrew Paul, Popular Science, 29 Oct. 2026

Eukaryotic organisms are reported less often than bacteria in extreme conditions, and based on observations from fungi at 140 F (60 C), scientists had theorized that eukaryotic life is not physically possible beyond 143 F (62 C). — Kristen Skruber, The Conversation, 29 Oct. 2026

Others theorized hopefully that there could be enormous economic opportunities. — Adam Kovac, Scientific American, 29 Oct. 2026

Word History

First Known Use

1644, in the meaning defined at transitive sense 1

Rhymes for theorize

• advise
• applies
• apprise
• arise
• assize
• baptize
• belies
• bitwise
• capsize
• chastise
• chordwise
• clockwise

Kids Definition

theorize

verb

the·​o·​rize ˈthē-ə-ˌrīz 

theorized; theorizing

: to form a theory : speculate

theorizer noun