estrus

/EH1 S T R AH0 S/
noun
  1. 1

    A biting fly of the genus Oestrus; a botfly.

  2. 2

    A bite or sting.

  3. 3

    A passion or frenzy.

  4. 4

    A female animal's readiness to mate; heat, rut.

Source: https://en.wiktionary.org/wiki/estrus, https://en.wiktionary.org/wiki/oestrus