underhand

You know I don't want to mix myself up with your underhand dealings.

And he recalled his own bootless wickedness and underhand intrigues.

Depend upon it, there has been some underhand influence at work.

If punished, he would continue his misdeeds in an underhand way.

Underhand, clandestine information you get is no more than dishonesty on your part.

I object as much, if not more, to his underhand concealment of this, than I do to the fact itself.

"Probably he was up to some underhand work," observed Walsh.

The offices which I have myself obtained I never strove for by any underhand means.

I do not wish to employ strong language, but I do consider it underhand.

But if she wants to do underhand things she should change her bonnet and cloak.