- an insane person
- a person who has an obsession with or excessive enthusiasm for something
- Tom is a maniac.
- She works like a maniac.
- You're driving like a maniac!
- He works like a maniac.
- Tom drives like a maniac.
- Oh, the driver is a maniac.
- There's a homicidal maniac on the loose!
- He came tearing around the corner, driving like a maniac, going like a house afire.
- I can understand German as well as the maniac that invented it, but I talk it best through an interpreter.
- Always program as if the person who will maintain your code is a maniac serial killer who knows where you live.