noun
- a person who behaves in a crazy or eccentric way
Usage: slang; informal
adjective
- crazy or mentally unbalanced
Usage: slang; informal
Examples
- That wacko down the street collects old shopping carts.
- Don’t listen to him – he’s a complete wacko.
- She thinks her neighbor is some kind of wacko.
- His wacko theories about aliens made everyone laugh.
- The movie featured a wacko scientist as the villain.
- People called him wacko for his unusual inventions.