any of an order of slender-bodied insects that fliesy by day and have large, broad, often brightly coloured wings and long thin antennae: order Lepidoptera
a frivolous person, esp one chiefly occupied with the pursuit of pleasure
a swimming stroke executed on the front by moving both arms together forwards out of the water and then sweeping them back through the water while kicking the legs up and down together
informal (in pl) queasiness caused esp by nervous tension
[Old English buterflēoge, from butere butter + flēoge fly; perhaps from former belief that butterflies steal milk and butter]