Know why cattywampus was trending last week?
"to run away," 1861, American Civil War military slang, of unknown origin, perhaps connected to earlier use in northern England dialect with a meaning "to spill." Liberman says it "has no connection with any word of Greek, Irish, or Swedish, and it is not a blend" [contra De Vere]. He calls it instead an "enlargement of dial. scaddle 'scare, frighten.'" Related: Skedaddled; skedaddling. As a noun from 1870.