1. To bring one back to consciousness or alertness out of some state of unconsciousness. I find that I need two separate alarms to roust me out of sleep in the morning. No amount of noise could roust him out of his stupor.

2. To drive or force one out of or away from some place or thing. We'd been studying so long that a security guard eventually came to roust us out of the library. The government began deploying tear gas to roust protestors out of the camp. I sent Mike upstairs to roust his older brother out of bed.