noun
- a person who behaves in a crazy or eccentric way
Usage: slang; informal
adjective
- crazy or mentally unbalanced
Usage: slang; informal
Examples
- That whacko down the street collects old shopping carts.
- Don’t listen to him – he’s a complete whacko.
- She went totally whacko when she heard the news.
- The neighbors think we’re whacko for painting our house purple.
- Some whacko was shouting at pigeons in the park.
- His whacko theories about aliens made everyone uncomfortable.