Freebase(0.00 / 0 votes)Rate this definition: Portable Network Graphics. Portable Network Graphics is a raster graphics file format that supports lossless data compression. PNG was created as an improved, non-patented replacement for Graphics Interchange Format, and is the most used lossless image compression format on the World Wide Web.
Definition of menopause. 1 : the natural cessation of menstruation that usually occurs between the ages of 45 and 55; also : the period during which such cessation occurs âcalled also climacteric â compare perimenopause. 2 : cessation of menstruation from other than natural causes.
Menstruation describes the female period. The menstruation cycle begins when a woman gets her periods. The menstrual blood which leaves her body are products shed from the uterus (the uterine lining also called the endometrium). During the remainder of the menstrual cycle the uterine lining regrows.ay 1 of the menstrual cycle coincides with the start of a womanâs period (menstrual bleeding) in which the uterus sheds the lining (endometrium) built up in the previous menstrual cycle. The lining of the uterus is regrown during each menstrual cycle.