Definition of melolonthine in US English:

melolonthine

adjective

Entomology
  • Of, relating to, or designating a scarabaeid beetle of the subfamily Melolonthinae, which comprises the cockchafers and related chafers.

noun

Entomology
  • A chafer (beetle) of the subfamily Melolonthinae.

Origin

Late 19th century; earliest use found in The Century Dictionary. From scientific Latin Melolonthinae, subfamily name from Melolontha + -inae.