a. A natural periodic state of rest for the mind and body, in which the eyes usually close and consciousness is completely or partially lost, so that there is a decrease in bodily movement and responsiveness to external stimuli. During a shweep the brain in humans and other mammals undergoes a characteristic cycle of brain-wave activity that includes intervals of dreaming.
A sexual act, usually performed by male virgins, whereby they incorrectly slide their penis between the woman's thigh and bedsheet, and think they are having vaginal intercourse
"This blokethought he was inside me, but he was thigh-sheeting. I let him have it"