1. (Science: zoology) A genus of gadflies. The species which deposits its larvae in the nasal cavities of sheep is oestrus ovis.
2. A vehement desire; especially.
(Science: physiology) The periodical sexual impulse of animals; heat; rut.
Origin: L, a gadfly; also, frenzy, fr.Gr. Gadfly; hence, sting, fury, insane desire, frenzy.