Any of various insects of the order Lepidoptera, characteristically having slender bodies, knobbed antennae, and four broad, usually colorful wings. A person interested principally in frivolous pleasure: a social butterfly. Sports A swimming stroke in which a swimmer lying face down draws both arms upward out of the water, thrusts them forward, and draws them back under the water in an hourglass design while performing a dolphin kick. Sports A race or a leg of a race in which this stroke is swum. A feeling of unease or mild nausea caused especially by fearful anticipation. To cut and spread open and flat, as shrimp.