noun: a style of animation that originated and is still heavily centered in Japan.
The word 'anime' is based on the original japanese pronunciation of the american word 'animation.'
The stereotype of the anime style are characters with proportionally large eyes and hair styles and colors that are very colorful and exotic. The plots range from very immature (kiddy stuff), through teenage level, to mature (violence, content, thick plot). The classification of 'hentai' is given to animes of a stong sexual nature.
Although over 95% of anime has nothing perverted about it, most closed-minded idiots think anime is always a form of pronography.
Although most people stop watching 'cartoons' in their early teens, there are 'animes' for all age groups.