loco

1 of 4

adverb or adjective

lo·​co ˈlō-(ˌ)kō How to pronounce loco (audio)
: in the register as written
used as a direction in music

loco

2 of 4

noun

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

loco

3 of 4

verb

locoed; locoing; locos

transitive verb

1
: to poison with locoweed
2
: to make frenzied

loco

4 of 4

adjective

slang
: mentally disordered : frenzied

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
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
Yang’s Kitchen will donate a portion of the profits from the kanpachi poke as well the Zumi’s loco moco dish to the Hawaii Community Foundation’s Maui Strong Fund. Camryn Brewer, Los Angeles Times, 14 Aug. 2023 From special pizzas to Hawaiian-style loco moco plates to tiki cocktails, this week brings ways to raise money for charities helping those affected by the wildfires in Maui. Chris Kelly, Washington Post, 17 Aug. 2023 This week’s edition includes Hawaiian loco moco, the best roasted chicken, and silky Japanese curry. Soleil Ho, San Francisco Chronicle, 27 Aug. 2021 Available in a variety of fun flavors including cocoa loco and caramel apple, the bars are made in a dedicated nut-free and gluten-free facility and are free from 14 allergens. Good Housekeeping, 29 Mar. 2023 The 24-hour eatery Cadillac Diner serves a fantastic loco moco, a classic Hawaiian plate lunch. Lori A. May, Chron, 19 Mar. 2023 And the oversize Hawaiian loco moco — which could be split between two people — was reimagined with some flavorful twists. San Diego Union-Tribune, 27 Jan. 2023 Daisy Edgar-Jones can do the loco-motion! On the Golden Globes 2023 red carpet on Tuesday, Edgar-Jones, 24, told E! Tommy McArdle, Peoplemag, 10 Jan. 2023 Others are traced to Puerto Rican communities as far away as Hawaii, such as pastele stew served over rice and topped with an egg, loco moco style. Los Angeles Times, 21 Dec. 2022
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

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'loco.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Adverb or adjective

Italian dialect, there, from Latin in loco in the place

Noun

Mexican Spanish, from Spanish, crazy

Adjective

Spanish

First Known Use

Adverb Or Adjective

1786, in the meaning defined above

Noun

1844, in the meaning defined above

Verb

1884, in the meaning defined at sense 1

Adjective

1852, in the meaning defined above

Time Traveler
The first known use of loco was in 1786

Dictionary Entries Near loco

Cite this Entry

“Loco.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/loco. Accessed 20 Apr. 2024.

Kids Definition

loco

adjective
lo·​co
ˈlō-kō
slang
: not sane : crazy

Medical Definition

loco

1 of 2 noun
lo·​co ˈlō-(ˌ)kō How to pronounce loco (audio)
plural locos or locoes
: any of several plants (genera Astragalus and Oxytropis) of western North America that contain a toxin that causes locoism in livestock when ingested in large quantities : locoweed

loco

2 of 2 transitive verb
: to poison with locoweed
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