1. Also called May beetle. any of several large, brown beetles of the genus Phyllophaga, of the scarab family, appearing in late spring and early summer.
2. See green June beetle.
3. Chiefly Northern and North Midland U.S.a firefly. Also,June'bug".
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.