loco
1 of 4adverb or adjective
lo·co
ˈlō-(ˌ)kō 
: in the register as written
—used as a direction in music
plural locos or locoes
: any of several leguminous plants (genera Astragalus and Oxytropis) of western North America that contain a toxin that causes locoism especially in livestock when ingested in large quantities : locoweed
locoed; locoing; locos
Synonyms
Verb
Adjective
- balmy
- barmy [chiefly British]
- bats
- batty
- bedlam
- bonkers
- brainsick
- bughouse [slang]
- certifiable
- crackbrained
- cracked
- crackers
- crackpot
- cranky [dialect]
- crazed
- crazy
- cuckoo
- daffy
- daft
- demented
- deranged
- fruity [slang]
- gaga
- haywire
- insane
- kooky
- kookie
- loony
- looney
- loony tunes
- looney tunes
- lunatic
- mad
- maniacal
- maniac
- mental
- meshuga
- meshugge
- meshugah
- meshuggah
- moonstruck
- non compos mentis
- nuts
- nutty
- psycho
- psychotic
- scatty [chiefly British]
- screwy
- unbalanced
- unhinged
- unsound
- wacko
- whacko
- wacky
- whacky
- wud [chiefly Scottish]
Examples of loco in a Sentence
Verb
years of living alone had clearly locoed the old rancher
Adjective
The crowd went loco when she walked out on the stage.
He's not just weird, he's positively loco.
Recent Examples on the Web
Jen Murphy, Outside Online, 29 Dec. 2022
Michael Ruiz, Fox News, 15 Oct. 2024
The combinations are spectacular: think abalone-like locos with peas and a touch of grapefruit foam paired with a green tea from Sichuan, China.
—Nicholas Gill, TIME, 25 July 2024
Andy Kessler, WSJ, 2 July 2017
As one of my colleagues said, this was straight loco.
—Ryu Spaeth, New Republic, 28 July 2017
See all Example Sentences for loco 
Examples are automatically compiled from online sources to
show current usage.
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Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
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Adverb or adjective
Breakfast hits include mahi eggs Benedict and loco moco, a hearty Hawaiian staple of eggs, a beef patty, and steamed rice smothered in a rich gravy.
—Jen Murphy, Outside Online, 29 Dec. 2022
Noun
Tren de Aragua, the Venezuelan prison gang whose name means Train of Aragua, is putting the loco in locomotive with a New York City robbery spree that sees its young members repeatedly stay out of jail.
—Michael Ruiz, Fox News, 15 Oct. 2024
The combinations are spectacular: think abalone-like locos with peas and a touch of grapefruit foam paired with a green tea from Sichuan, China.
—Nicholas Gill, TIME, 25 July 2024
Adjective
Real investors survey the landscape and look for signs of a market gone loco.
—Andy Kessler, WSJ, 2 July 2017
As one of my colleagues said, this was straight loco.
—Ryu Spaeth, New Republic, 28 July 2017
See all Example Sentences for loco
Dictionary Entries Near loco
Cite this Entry
“Loco.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/loco. Accessed 17 Dec. 2024.
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