The Ninjina (Ninja + Vagina) is the mascot for the "Pussy Air Freshener," a cherry scented adult novelty product that you can display in your car, garage, or dorm room.
Phil: "Dude, it's pretty rank in here."
Jack: "Yeah, I wish the Ninjina would pay us a visit."
Phil: "The Ninjina?"
Jack: "Yeah, the Ninjina. He suddenly appears in a puff of smoke, and throws Pussy Air Fresheners like Chinese stars."
Phil: "He what?"
Jack: "You heard me."
v. To be or act like a ninja; to perform any ninja related actions (steal, sneak, kill, fight, attack); to perform with stealth or skill; to use any form of martial arts.
They must ninjiate into house, or there will surely be consequences.
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.