Obsesivo (en. Obsessive)
/ob-se-ˈsi-vo/
Slang Meanings
Focused
He is so obsessive in his studies that he doesn't care about anything else.
Está tan obsesivo en su estudio que no le importa nada más.
Freak
That guy is a freak for his obsession with video games.
Ese tipo es un freak por su obsesión con los videojuegos.