whacko

/ˈwækoʊ/
noun
  1. A person who is crazy or eccentric.
    • Don't listen to that whacko; he doesn't know what he's talking about.
    • The town had a reputation for attracting whackos.
    • Some whacko tried to sell me a pet rock.
Synonyms
adjective
  1. Crazy, eccentric, or irrational in behavior or ideas.
    • Her whacko ideas about gardening actually worked.
    • That conspiracy theory is completely whacko.
    • He's a bit whacko, but he's harmless.
Antonyms
What does "whacko" mean? | whatsthatwordmean | whatsthatwordmean