A word that describes a unreliable person?

Answer 1

unreliable...

untrustworthy...?

--or a more defined answer?

capricious, deceitful, deceptive, delusive, disreputable, dubious, erroneous, fake, fallible, false, fickle, fly-by-night, furtive, hallucinatory, hollow, implausible, inaccurate, inconstant, irresponsible, makeshift, meretricious, mistaken, pretended, pseudo, questionable, sham, shifty, specious, treacherous, tricky, uncertain, unconvincing, undependable, underhand, underhanded, unfaithful, unsound, unstable, unsure, untrue, untrustworthy, vacillating, wavering, weak ambiguous, astucious, beguiling, bum*, catchy, crafty, cunning, deceitful, deceiving, deluding, delusive, delusory, designing, disingenuous, fake, fallacious, false, fishy, foxy, fraudulent, illusory, imposturous, indirect, insidious, lying, misleading, mock, oblique, off*, phony, plausible, rascal, roguish, scheming, seeming, serpentine, shifty, slick, slippery, sly, sneaky, snide, specious, spurious, subtle, treacherous, tricky, two-faced, underhand, underhanded, unreliable , wily