Ascarid \As"ca*rid\, n.; pl. {Ascarides}or {Ascarids}. [NL. ascaris, fr. Gr. ?.] (Zool.) A parasitic nematoid worm, especially the roundworm, {Ascaris lumbricoides}, often occurring in the human intestine, and allied species found in domestic animals; also commonly applied to the pinworm ({Oxyuris}), often troublesome to children and aged persons. [1913 Webster]