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

The system targets operations in environments where GPS signals or communications links become unreliable. — Aamir Khollam, Interesting Engineering, 4 Nov. 2026

There was a time in this country when arts criticism was valued as a worthwhile pursuit unto itself, as opposed to a wonky and unreliable component of the promotional apparatus. — David Ehrlich, IndieWire, 3 Nov. 2026

Courts so far have sided with California and Los Angeles County's arguments that the federal government's list is unreliable, and that creating a novel system to segregate ballots while voting is already underway is infeasible. — Jude Joffe-Block, NPR, 2 Nov. 2026

That doesn't just show that Kioxia is a mess, but also that the group is unreliable despite SK Hynix's extraordinary numbers. — Jim Cramer, CNBC, 1 Nov. 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