Screaming is a gerund or present participle of a word "Scream."
Scream- 1. Give a long, loud, piercing cry or cries expressing extreme emotion or pain.
2. Urgently and vociferously call attention to one's views or feelings, especially ones of anger or distress.
3. Make a loud, high-pitched sound.
4. Turn informer.
Poonam and Prabh were screaming on seeing the thief in the house.