Behavior characterized by a statement that insinuates one’s own awesomeness in an unassuming, detached or even self-deprecating manner - i.e. bragging while trying not to seem like you're bragging.
1. Matt was being so passive-impressive when he told us he felt like a total dipshit after realizing he had spinach in his teeth while he was talking to Colin Kaepernick at that party last night.
2. I hate when people tweet passive-impressive stuff like: “Gosh, I am really dragging ass today after running 30 miles before work."