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.
Best Answer: Hi, You mean monthly period of girls. Monthly period is called Menstruation. Mestruation is a normal part of a womanâs reproductive cycle. The ovary periodically releases an egg. It also releases a hormone called oestrogen, which stimulates the lining of the uterus to grow and get prepared to receive the fertilized egg. If, however, the egg does not get fertilized, the uterus sheds its lining resulting in menstrual flow. This flow repeats itself in a cycle of approximately 28 days until a woman gets pregnant or has approached menopause.