undefined

adjective

un·​de·​fined ˌən-di-ˈfīnd 

: not defined: such as

a

: not clearly or precisely shown, described, or limited

undefined rules

undefined powers

a vague, undefined feeling of dread

… the true outlines of Clinton's foreign policy remain undefined.

—William Greider

b

: not provided with a definition

an undefined dictionary entry

Synonyms of undefined

• vague
• faint

Examples of undefined in a Sentence

plagued by undefined worries that kept her awake at night

Recent Examples on the Web

Loose contracts, unclear ownership, poor communication trails, rushed partnerships and undefined expectations create openings that later turn into major problems. —Michael Gargiulo, Forbes.com, 22 May 2026

Then there was the late emergence of the Sedin twins as contenders for the seat of power, the franchise legends set to take on some undefined position of significant authority. —Thomas Drance, New York Times, 13 May 2026

The bodies float in an undefined space, at once intimate and strangely cosmic. —George Nelson, ARTnews.com, 8 May 2026

Create zones that give your patio a purpose The most functional patios don’t try to do everything in one undefined space. —Lauren Jarvis-Gibson, Sacbee.com, 30 Apr. 2026

Word History

First Known Use

1611, in the meaning defined above

Rhymes for undefined

• aligned
• alined
• assigned
• behind
• combined
• confined
• consigned
• crosswind
• declined
• defined
• designed
• divined