Nightfall meaning: Nightfall is considered normal if it occurs

Nightfall is considered normal if it occurs in a controlled frequency which is about two nightfall per week. For teen males, the mean frequency of nightfall is approximately 0.36 times a week while for 40-year-old males, the nightfall mean frequency is 0.18 times a week. Nightfall definition: the coming of night; the end of daylight; dusk.. See examples of NIGHTFALL used in a sentence. Nightfall or wet dreams is a natural but often misunderstood phenomenon. To know more about nightfall and how to stop it read the article. A nightfall, known scientifically as a nocturnal emission, and also informally known as a wet dream, sex dream, or sleep orgasm, is a spontaneous orgasm that involves ejaculation for males and vaginal wetness or an orgasm (or both) for females during sleep.