adjective
1.
not to be counted on
it is certain that much of the testimony was unreliable
Synonyms: dubious, fly-by-night, questionable, trustless, undependable, unsure, untrustworthy, untrusty
Related Word: fickle, inconstant, unstable, vacillating; faithless, false, untrue; falsehearted, perfidious; shifty, slick, slippery, tricky; inaccurate, inexact, unfaithful
Idioms: not to be depended ( or relied) on
Contrasted words: dependable, trustworthy, trusty; constant; faithful, true
Antonyms: reliable
2.
Synonyms: unsafe , unassured, undependable, untrustworthy
Antonyms: reliable