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

• vague
• faint

Examples of undefined in a Sentence

plagued by undefined worries that kept her awake at night

Recent Examples on the Web

The two nations maintain a heavy military presence along their 2,100-mile (3,379-kilometer) de facto border, known as the Line of Actual Control (LAC) – a boundary that remains undefined and has been a persistent source of friction since their bloody 1962 war. —Simone McCarthy, CNN Money, 31 Aug. 2025

When time off is undefined, the good ones don’t take PTO. —Preston Fore, Fortune, 23 Aug. 2025

Unlike other startups that are chasing the still relatively undefined goal of achieving AGI (an AI system that rivals human intelligence), Cohere is focused on how AI can best be used to increase productivity, Cohere cofounder Nick Frosst told me last week. —Rashi Shrivastava, Forbes.com, 19 Aug. 2025

The younger Bayh is largely undefined. —Hayleigh Colombo, IndyStar, 19 Aug. 2025

Word History

First Known Use

1611, in the meaning defined above

Rhymes for undefined

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