deceitful

When peace was proclaimed, his deceitful conduct was apparent to both combatants.

And then, her temper’s pretty quick, I guess; but there’s one comfort, a child that has a quick temper, just blaze up and cool down, ain’t never likely to be sly or deceitful.

I had never realized until that moment, Marilla, that what I was doing was deceitful.

“Nothing is more deceitful,” said Darcy, “than the appearance of humility.