wacko

1 of 3

adjective (1)

ˈwa-(ˌ)kō How to pronounce wacko (audio)
variants or less commonly whacko
Synonyms of wackonext
: wacky

wacko

2 of 3

noun

variants or less commonly whacko
: a person who is wacky
also : psycho entry 1

whacko

3 of 3

adjective (2)

less common spelling of wacko

: wacky

Synonyms of wacko

Relevance

Adjective (1)

Noun

See All Synonyms & Antonyms in Thesaurus

Examples of wacko in a Sentence

Adjective (1) a completely wacko obsession with cleaning Noun She's nice but her sister's a real wacko. a completely wacko obsession with cleaning
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
This wacko crew was one of the greatest things in the history of television. — Jordan Hoffman, EW.com, 14 Aug. 2025 Sounds crazy, but when has UAB football not been completely wacko. — Joseph Goodman | [email protected], al, 16 Dec. 2022
Noun
People who see ghosts tend to see the same ghost wafting down the same staircase, but none of the characters populating Leo’s wacko hallucinations have returned for a repeat perfor-mance. — Literary Hub, 10 Apr. 2026 This wacko crew was one of the greatest things in the history of television. — Jordan Hoffman, EW.com, 14 Aug. 2025 See All Example Sentences for wacko

Word History

Etymology

Adjective (1)

by alteration

First Known Use

Adjective (1)

1965, in the meaning defined above

Noun

1936, in the meaning defined above

Time Traveler
The first known use of wacko was in 1936

Rhymes for wacko

See All Rhymes for wacko

Browse Nearby Words

wackiness
wacko
wacky
See all Nearby Words

Cite this Entry

“Wacko.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/wacko. Accessed 7 Jul. 2026.

Copy Citation
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

Is that lie 'bald-faced' or 'bold-faced'?

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?

Commonly Misspelled Words

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)
See More

Popular in Wordplay

See More

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

One-Word Oxymorons: Bittersweet, Spendthrift, and More

Ten Words Ending with a Silent ‘T’

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

Is that lie 'bald-faced' or 'bold-faced'?

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
hangman letters and game
Hangman Lightning Round Figure out which word fits in the blanks.
See All