Short for crayfish, a freshwater creature that looks like a small lobster; also modern slang meaning 'crazy' or 'wild.'
From Middle French 'crevis,' related to 'crevice.' The animal name shortened to 'cray.' Modern slang 'cray' for crazy emerged in African American Vernacular English in the 2000s.
It's wild that 'cray' has two completely different meanings—the actual freshwater crustacean that's been called that for centuries, and then suddenly in the 2000s, teenagers started using it as slang for 'crazy' because they sound similar!
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