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

James Hager’s dramatic body camera footage, which showed him being battered, and Mansfield theorizes Lopez feared a conviction was likely. — David Goodhue, Miami Herald, 2 Oct. 2026

Some readers have long theorized that Jeremy somehow coordinated that bike accident prior to the meeting. — Glamour, 2 Oct. 2026

In the centuries since, some scholars have theorized that powerful relatives and political rivals conspired to have Báthory imprisoned for their own benefit. — Caroline Blair, PEOPLE, 25 Sep. 2026

Yet, despite microquasars having been theorized to exist within our galaxy for around three decades, this one has avoided detection because it is blocked by a thick wall of interstellar gas and dust. — Robert Lea, Space.com, 24 Sep. 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