To turn the electrical power on to a device as a precondition to make it operational.(verb)
To become ready for operation as a result of the provision of electrical power.(verb)
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Use "power up" in a sentence
"In order to achieve the transcendental Illumination, a yogin must redirect the course of sexual power up the median nerve to the brain."
"In-demand talent and, by extension, their representation holds a certain amount of power up until the breaking point—that point where the economics no longer make sense."