LOCO

I. adverb or adjective Etymology: Italian dialect, there, from Latin in ~ in the place Date: circa 1801 in the register as written, II. noun (plural ~s or ~es) Etymology: Mexican Spanish, from Spanish, crazy Date: 1844 ~weed , ~ism , III. transitive verb Date: 1884 to poison with ~weed, to make frenzied or crazy, IV. adjective Etymology: Spanish Date: 1887 mentally disordered ; crazy , frenzied