Origin of reliable

First recorded in 1560–70; rely + -able
Related formsre·li·a·bil·i·ty, re·li·a·ble·ness, nounre·li·a·bly, adverbnon·re·li·a·ble, adjectivenon·re·li·a·ble·ness, nounnon·re·li·a·bly, adverbqua·si-re·li·a·ble, adjectivequa·si-re·li·a·bly, adverbul·tra·re·li·a·ble, adjectiveul·tra·re·li·a·ble·ly, adverb

Synonyms for reliable

trusty, authentic, consistent. 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.

Antonyms for reliable Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for non-reliable


  1. able to be trusted; predictable or dependable
Derived Formsreliability or rare reliableness, nounreliably, adverb
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

Word Origin and History for non-reliable



1560s, raliabill, Scottish; see rely + -able. Not common before 1850; and sometimes execrated thereafter in Britain as an Americanism because it involves a use of -able different from its use in provable, etc., but defended (by OED, Century Dictionary, etc.) on grounds of use of the suffix in available, laughable, etc.. Related: Reliably.

Online Etymology Dictionary, © 2010 Douglas Harper