Wacko Belongs to a Family of Nonsense Words
Wacko is slang for someone eccentric or mad. It is one of several English words built from the sound whack.
Wacko is informal slang for a person considered eccentric or mad. It sits in a small family built on *whack*, the sound of a blow: *wacky* appears in the 1930s from the idea of someone who has been hit on the head, and *wacko* follows in the 1970s with the *-o* ending English uses for informal nouns, as in *weirdo*, *sicko* and *cheapo*. The words are dismissive rather than clinical, and English has many gentler options for eccentricity.
- An eccentric person. *Called a wacko.*
- Wacky — the adjective. *A wacky idea.*
- Whack — the source. *A whack.*
- Weirdo — the same -o pattern. *A weirdo.*
- American slang. *From the 1970s.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | wacko | A wacko. |
| Plural | wackos | Wackos. |
| Adjective | wacky | Wacky. |
| Base | whack | A whack. |
| Register | slang | Informal. |
- They dismissed him as a wacko.Slang.
- A wacky comedy.Adjective.
- The -o ending marks informality.Formation.
The informal -o ending
- Wacko — from wacky
- Weirdo — from weird
- Sicko — from sick
- Cheapo — from cheap
- All carry a dismissive or jokey tone
From *wacky*, itself from *whack*, with the informal noun suffix *-o*. American, from the 1970s.
Where does wacky come from?
From whack, the sound of a blow, on the idea of someone who has been hit on the head. It appears in the 1930s.
What does the -o ending do?
It marks a word as informal and often dismissive, as in weirdo, sicko and cheapo.