not able to be relied on as honest or truthful.
“He was generally considered to be a devious and untrustworthy human being”
dishonest, deceitful, not to be trusted, double-dealing, treacherous, traitorous, two-faced, Janus-faced, unfaithful, duplicitous, dishonourable, unprincipled, unscrupulous, corrupt, shady, shifty, underhand; unreliable, undependable, capricious, fickle, slippery;
informal iffy; informal dodgy; informal shonky
“our products are exposed to an untrustworthy treasurer”;