gnat

noun

• a small two-winged fly that resembles a mosquito. Gnats include both biting and non-biting forms, and they typically form large swarms.

  • Several families, especially Culicidae (the biting gnats), which includes the common gnat (Culex pipiens)
• a person regarded as tiny or insignificant:she’d be marking O’Brien—a gnat trying to curb an elephant