OESTRUS

I. ˈestrəs, ˈēs- noun

Etymology: Latin, gadfly, from Greek oistros gadfly, desire, frenzy — more at ire

1. -es archaic : a biting or tormenting fly

2. capitalized

[New Latin, from Latin]

: the type genus of Oestridae comprising the sheep botfly

II.

or oestrum

variant of estrus