reliable

American

[ri-lahy-uh-buhl] / rɪˈlaɪ ə bəl /

adjective

that may be relied on or trusted; dependable in achievement, accuracy, honesty, etc..

reliable information.

Synonyms:

consistent, authentic, trusty

Antonyms:

deceitful, questionable, undependable

reliable British

/ rɪˈlaɪəbəl /

adjective

able to be trusted; predictable or dependable

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Related Words

Reliable, infallible, trustworthy apply to persons, objects, ideas, or information that can be depended upon with confident certainty. Reliable suggests consistent dependability of judgment, character, performance, or result: a reliable formula, judge, car, meteorologist. Infallible suggests the complete absence of error, breakdown, or poor performance: an infallible test, system, marksman. Trustworthy emphasizes the steady and honest dependability which encourages one's confidence, belief, or trust: trustworthy and accurate reports.

Other Word Forms

nonreliable adjective
nonreliableness noun
nonreliably adverb
quasi-reliable adjective
quasi-reliably adverb
reliability noun
reliableness noun
reliably adverb
ultrareliable adjective
ultrareliablely adverb

Etymology

Origin of reliable

First recorded in 1560–70; rely + -able

Compare meaning

How does reliable compare to similar and commonly confused words? Explore the most common comparisons:

reliable vs. dependable

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

If anything, that underscores the crypto’s one reliable trait—its remarkable staying power despite all the naysayers.

From Barron's • Apr. 3, 2026

Fast, reliable wireless connections are essential in everyday life.

From Science Daily • Apr. 2, 2026

"AI tools aren't 100% reliable — they can fail in subtle ways and yet operators continue to over-trust them," she told NBC News last month.

From BBC • Apr. 1, 2026

“Secure ballot envelope identifiers provide a reliable, auditable mechanism to enforce Federal law without unduly burdening or infringing on the rights of eligible voters,” the order reads.

From Los Angeles Times • Mar. 31, 2026

The huge, slow-moving dirigibles were later replaced by more reliable long-range airplanes, such as the German Gotha bombers that carried out daylight raids on London.

From "The War to End All Wars: World War I" by Russell Freedman

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023