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

While fans have long theorized that the Marvel star is the voice behind the character, Matheson confirms the actor’s cameo to PEOPLE. — Kirsten Acuna, PEOPLE, 26 June 2026

The other hypothesis theorizes supermassive black hole seeds came from a large gas cloud collapsing, due to its large mass and strong gravity, into a black hole. — Mary Ogborn, The Conversation, 25 June 2026

Historians theorize the unidentified vessel may also have originated in the Netherlands. — Andrew Paul, Popular Science, 25 June 2026

In Second Nature, scientists theorize that Darwin couldn’t help but impose his own heterosexual ideations on animal reproduction, mainly that animals only copulate for the purposes of reproduction, with males being the aggressors and females fluttering their eyelids behind lace fans, or something. — Rachel Brodsky, Rolling Stone, 20 June 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