Utter, gleeful chaos — one eye wide, one eye squeezed shut, tongue lolling out, meant to convey 'crazy in a fun way' or wild, uninhibited silliness. Introduced in Unicode 8.0 (2015), it was designed explicitly to be more extreme and absurd than the existing tongue-out faces, and it's since become a favorite for 'unhinged but happy' energy.
Keywords: crazy, eye, eyes, face, goofy, large, small, zany