loco
1 of 4adverb or adjective
lo·co ˈlō-(ˌ)kō 
: in the register as written —used as a direction in music
loco
2 of 4noun
plural locos or locoes
1
: locoweed
2
: locoism
loco
3 of 4verb
locoed; locoing; locos
transitive verb
1
: to poison with locoweed
2
: to make frenzied or crazy
loco
4 of 4adjective
slang
: mentally disordered : crazy, frenzied
Synonyms
Verb
- crack
- craze
- derange
- frenzy
- madden
- unbalance
- unhinge
- unstring
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]
See all Synonyms & Antonyms 
Example Sentences
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
Elena Kadvany, San Francisco Chronicle, 2 Aug. 2022 The menu is inspired by both of their backgrounds, with iconic Pinoy dishes like chicken adobo, sisig and longsilog and Hawaiian items like loco moco, Spam and eggs, and malasadas. Cesar Hernandez, San Francisco Chronicle, 25 July 2022 It’s a Hawaiian-leaning menu with garlic shrimp over rice and plates of loco moco. Jenn Harriscolumnist, Los Angeles Times, 27 June 2022 Or fresh-cut strawberries covered in a thin layer of cream or even elotes loco, the popular street snack that puts a fright wig of condiments on a humble ear of corn. Washington Post, 8 Nov. 2021 The Passion mango is a variation of the popular mangoneada or mango loco flavor, which often includes fresh pieces of mango laced with fruity Chamoy sauce and Tajin chile powder. Andi Berlin, The Arizona Republic, 16 Sep. 2021 Professional and amateur cooks compete for bragging rights in this festival and cook-off devoted to the homey South Texas staple fideo loco. Jim Kiest And Deborah Martin, San Antonio Express-News, 4 Nov. 2021 Look for future specials like a curry loco moco with Japanese curry instead of the typical gravy. Elena Kadvany, San Francisco Chronicle, 18 Oct. 2021 Raspados Imperial has both a mango loco and a passion mango flavor on their menu. Andi Berlin, The Arizona Republic, 16 Sep. 2021 Andy Kessler, WSJ, 2 July 2017 As one of my colleagues said, this was straight loco. Ryu Spaeth, New Republic, 28 July 2017 See More
Noun
Morning Wood, a beloved Hawaiian-Japanese brunch restaurant that drew long lines for enormous plates of gravy-dripping loco moco and chewy matcha mochi pancakes, is coming back to the Peninsula. Elena Kadvany, San Francisco Chronicle, 2 Aug. 2022 The menu is inspired by both of their backgrounds, with iconic Pinoy dishes like chicken adobo, sisig and longsilog and Hawaiian items like loco moco, Spam and eggs, and malasadas. Cesar Hernandez, San Francisco Chronicle, 25 July 2022 It’s a Hawaiian-leaning menu with garlic shrimp over rice and plates of loco moco. Jenn Harriscolumnist, Los Angeles Times, 27 June 2022 Or fresh-cut strawberries covered in a thin layer of cream or even elotes loco, the popular street snack that puts a fright wig of condiments on a humble ear of corn. Washington Post, 8 Nov. 2021 The Passion mango is a variation of the popular mangoneada or mango loco flavor, which often includes fresh pieces of mango laced with fruity Chamoy sauce and Tajin chile powder. Andi Berlin, The Arizona Republic, 16 Sep. 2021 Professional and amateur cooks compete for bragging rights in this festival and cook-off devoted to the homey South Texas staple fideo loco. Jim Kiest And Deborah Martin, San Antonio Express-News, 4 Nov. 2021 Look for future specials like a curry loco moco with Japanese curry instead of the typical gravy. Elena Kadvany, San Francisco Chronicle, 18 Oct. 2021 Raspados Imperial has both a mango loco and a passion mango flavor on their menu. Andi Berlin, The Arizona Republic, 16 Sep. 2021 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 More 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 at sense 1
Verb
1884, in the meaning defined at sense 1
Adjective
1852, in the meaning defined above
Phrases Containing loco
Medical Definition
loco 1 of 2
noun
lo·co ˈlō-(ˌ)kō
plural locos or locoes
1
: locoweed
2
: locoism
loco
2 of 2transitive verb
: to poison with locoweed
loco 1 of 2
adjective
as in lunatic
having or showing a very abnormal or sick state of mind that dog's plumb loco, just running around in circles all day long Synonyms & Similar Words
Relevance
- lunatic
- nuts
- psychotic
- mad
- maniac
- gaga
- insane
- psycho
- crazy
- mental
- cuckoo
- maniacal
- paranoid
- batty
- wacko
- loony
- deranged
- crazed
- bonkers
- scatty
- looney
- disturbed
- unhinged
- nutty
- demented
- certifiable
- around the bend
- ballistic
- barmy
- daft
- haywire
- eccentric
- daffy
- moonstruck
- bedlam
- cracked
- whacko
- bats
- strange
- crackpot
- crackers
- whacky
- unbalanced
- brainsick
- bughouse
- wacky
- depressed
- meshuga
- paranoidal
- off
- out to lunch
- screwy
- kooky
- kookie
- meshugah
- fruity
- loony tunes
- looney tunes
- obsessed
- crackbrained
- meshuggah
- meshugge
- odd
- non compos mentis
- unsound
- foolish
- irrational
- queer
- schizoid
- dotty
- fey
- nuclear
- cranky
- neurotic
- oddball
- distracted
- schizophrenic
- wud
- out of one's mind
- teched
- off one's gourd
- distraught
- balmy
- potty
- frantic
- off one's rocker
- loopy
- delusionary
- paranoiac
- touched
- disordered
- hysteric
- off one's head
- bananas
- sociopathic
- tetched
- aberrant
- out of one's head
- hysterical
- ape
- delusional
- berserk
- delirious
- unreasonable
- paranoic
- amok
- raving
- pixillated
- monomaniac
- pixilated
- amuck
- monomaniacal
- fixated
- witless
- obsessive-compulsive
- wigged-out
- frenzied
- senseless
Antonyms & Near Antonyms
- sound
- sane
- compos mentis
- balanced
- normal
- reasonable
- clear
- wise
- sensible
- rational
- healthy
- uncrazy
- judicious
- lucid
- well-adjusted
- unneurotic
loco
2 of 2verb
as in to craze
to cause to go insane or as if insane years of living alone had clearly locoed the old rancher Synonyms & Similar Words
- craze
- frenzy
- unbalance
- madden
- bother
- derange
- upset
- crack
- confuse
- distract
- disturb
- annoy
- unsettle
- unstring
- disquiet
- unhinge
- agitate
- vex
- discompose
- perturb
- irritate
Antonyms & Near Antonyms
- quiet
- relax
- calm
- settle
- tranquillize
- tranquilize
- soothe