oestrus
oestrus , noun
[Latin, a gadfly; also, frenzy, from Greek {not transcribed} gadfly; hence, sting, fury, insane desire, frenzy.]
1.
(Zoology) A genus of gadflies. The species which deposits its larvae in the nasal cavities of sheep is oestrus ovis.
2.
A vehement desire.
3.
(Physiology) The periodical sexual impulse of animals; the period during which female animals are most receptive to males; heat; rut.