What's the "een" in Halloween?
1844, American English, from Spanish loco (adj.) "insane," of uncertain origin, perhaps from Arabic lauqa, fem. of 'alwaq "fool, crazy person." Loco-weed (1877) was name given to species of western U.S. plants that cause cattle and horse diseases that make them stagger and act strangely.
Crazy; nuts: He took one look and just went loco (1887+)noun
: She's acting like a loco
[fr Spanish, ''insane'']
A locomotive (1940s+ Railroad)