oestrum
nounEtymology From Latin oestrum, variant of oestrus.
1
Obsolete A biting insect; a gadfly or botfly.
- In the œstrum or gadfly, the wimble draws out like the pieces of a spy-glass […].1802, William Paley, Natural Theology, section XIX:
2
Archaic, Figuratively Something that stings or incites one to frenzy or action; an impulse or passion.
3
Biology, Medicine, Natural sciences, Physiology, Sciences, Zoology Archaic Estrus.