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

Thanks to a particularly blurry playoff picture, many of the buyers and sellers remain undefined. — Patrick Mooney, New York Times, 16 July 2026

The message of the Corcoran cancellation was that crossing some undefined line of decency gave the government license to come after you. — Louis Menand, New Yorker, 13 July 2026

But their relationship remains undefined, and kind of over after Carter drunkenly ruins Beulah's big party. — Bryan Alexander, USA Today, 3 July 2026

Anyway, things continue to be tenuous at The Bear, as Sydney, Richie, Natalie and Carmy are forced to adjust to their new status quo, with a wholly undefined new power structure. — Daniel Fienberg, HollywoodReporter, 25 June 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