Untrusty
The Century Dictionary and Cyclopedia
Not trusty; not worthy of confidence; unfaithful.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
not worthy of trust or belief
Word Usage
"Holding my rather untrusty camera in my hand ready for action, I began with some photos as the train crossed the Forth on the old rail bridge."
Equivalent
devious
fly-by-night
shady
shifty
slippery