zippery

flippant, off-the-cuff behavior from either a lack of sleep and/or too much coffee, usually accompanied by inane rambling

Molly: "What the heck is talking about?"
Mike: "Don't mind him, he's just being zippery."
Molly: "Why?"
Mike: "Finals week. He hasn't slept in a couple days."

by MC Duden February 6, 2020