Un′re‐li″a‐ble (?), a. Not reliable; untrustworthy. See Reliable. — Un′re‐li″a‐ble‐ness, n.
Alcibiades... was too unsteady, and (according to Mr. Coleridge's coinage) “unreliable;” or perhaps, in more correct English, too “unrelyuponable.” De Quincey.