Playing is a gerund or present participle of verb "PLAY."
1. Engage in activity for enjoyment and recreation rather than a serious or practical purpose.
2. Take part in (a sport).
3. Be cooperative.
4. Represent (a character) in a theatrical performance or a film.
5. Perform on (a musical instrument).
6. Move lightly and quickly, so as to appear and disappear; flicker.
7. Allow (a fish) to exhaust itself pulling against a line before reeling it in.
1. Children are playing in the ground.
2. The musician is playing a very sweet music.