perfidious

As adjectives the difference between perfidious and untruthful

is that perfidious is of, pertaining to, or representing perfidy; disloyal to what should command one's fidelity or allegiance while untruthful is not giving the truth; providing untrue facts; lying.

As adjectives the difference between pernicious and perfidious

is that pernicious is causing much harm in a subtle way while perfidious is of, pertaining to, or representing perfidy; disloyal to what should command one's fidelity or allegiance.

As an adjective perfidious

is of, pertaining to, or representing perfidy; disloyal to what should command one's fidelity or allegiance.

As a verb conspire is

.

As an adjective perfidious

is of, pertaining to, or representing perfidy; disloyal to what should command one's fidelity or allegiance.

As a noun traitor is

traitor.

As a proper noun bluff

is the southernmost town in the south island of new zealand, and seaport for the southland region.

As an adjective perfidious is

of, pertaining to, or representing perfidy; disloyal to what should command one's fidelity or allegiance.