1. Indirect, passive anything that people use to avoid demands or requests, avoid confrontation or purposely sabotage something for someone else.
2. First let me say that there are few things that anger me more than passive-aggressive behavior. It is passive. It is silent. It is not clever. If that is your only weapon, a much more direct person will one day call your spineless ass out in an absolutely raw and naked way, where there will be no where to hide.
Examples - accepting and invite you don't really want then taking an eternity getting ready so the event is conveniently missed. The silent treatment that can go on for days. Coworkers who agree with what you say and simply do nothing. Catty bitchy women and men. What's wrong? Nothing.
It gives me a headache to think of more examples.