Synonyms of the word

untrusty

• adj. Not trusty.

devious

• adj. Deviating; not straightforward or honest, not frank; not standard.

dishonest

• adj. Not honest.
• adj. Interfering with honesty.
• adj. (obsolete) Dishonourable; shameful; indecent; unchaste; lewd.
• adj. (obsolete) Dishonoured; disgraced; disfigured.

dishonorable

• adj. Without honor, or causing dishonor.
• adj. Lacking respect or ethical principles.

fly-by-night

• n. A creature which flies at night; a nocturnal flier or traveler.
• n. One who departs or flees at night in order to avoid creditors, law enforcement etc. (often used attributively).
• n. (idiomatic, derogatory) A person or business that appears and disappears rapidly, or gives an impression…
• n. (idiomatic, derogatory) A traveling businessman or tradesman.

shady

• adj. Abounding in shades.
• adj. Causing shade.
• adj. Overspread with shade; sheltered from the glare of light or sultry heat.
• adj. (informal) Not trustworthy; disreputable.
• adj. (Britain, slang) Mean, cruel.

shifty

• adj. Having the appearance of someone dishonest, criminal or unreliable; such as someone with shifty eyes.
• adj. Subject to frequent changes in direction.
• adj. Full of, or ready with, shifts or expedients.

slippery

• adj. Of a surface, having low friction, often due to being covered in a non-viscous liquid, and therefore hard…
• adj. (figuratively, by extension) Evasive; difficult to pin down.
• adj. (obsolete) Liable to slip; not standing firm.
• adj. Unstable; changeable; inconstant.
• adj. (obsolete) Wanton; unchaste; loose in morals.

tricky

• adj. hard to deal with, complicated.
• adj. adept at using deception.
• adj. (colloquial, slang) Relating to or associated with a prostitution trick.

undependable

• adj. Not dependable.

unfaithful

• adj. Not having religious faith.
• adj. Not keeping good faith; disloyal; not faithful.
• adj. Not honest or upright.
• adj. (translation studies) which doesn't faithfully render the meaning of the source language; incorrect.
• adj. Adulterous.

unreliable

• adj. Not reliable.

untrustworthy

• adj. Not deserving of trust; unreliable.