noun, plural sand·flies.
- any of several small, bloodsucking, dipterous insects of the family Psychodidae that are vectors of several diseases of humans.
- any of several other small, bloodsucking, dipterous insects, as one of the family Heleidae or Simuliidae.
noun plural -flies
- any of various small mothlike dipterous flies of the genus Phlebotomus and related genera: the bloodsucking females transmit diseases including leishmaniasis: family Psychodidae
- any of various similar and related flies
n.1748, from sand (n.) + fly (n.).