unreliable

adjective

un·​re·​li·​able ˌən-ri-ˈlī-ə-bəl 

: not reliable : undependable, untrustworthy

an unreliable friend

an unreliable source of funding

an unreliable car

unreliability

ˌən-ri-ˌlī-ə-ˈbi-lə-tē 

noun

the unreliability of the data

a person with a reputation for unreliability

unreliably

ˌən-ri-ˈlī-ə-blē 

adverb

a method that works unreliably

Examples of unreliable in a Sentence

Recent Examples on the Web

Additionally, detection may be unreliable if a wall or other obstacle, like a human body, interferes with a signal. — Ashley Belanger, ArsTechnica, 21 Aug. 2026

Researchers point to various challenges to help explain why so many students frequently miss school, including poverty, unreliable transportation and housing instability. — Jerome A. Graham, The Conversation, 19 Aug. 2026

Move about wisely During peak summer, taxis and Ubers are limited, wait times can be long, and unreliable. — Chloe Sachdev, Condé Nast Traveler, 19 Aug. 2026

As the year’s midterm primaries draw to a close, Tuesday’s results in Florida, Wyoming and Alaska continued to underscore an unpredictable election season marked by unreliable polls, intra-party divides and surprise showings by political outsiders. — Christopher Buchanan, Los Angeles Times, 19 Aug. 2026

Word History

First Known Use

1810, in the meaning defined above

Rhymes for unreliable

• liable
• pliable
• triable
• viable
• classifiable
• justifiable
• modifiable
• notifiable
• satisfiable
• specifiable
• undeniable
• verifiable