Estrous (adjective)

1. Relating to or denoting a female mammal's menstrual cycle and reproductive state, especially in reference to the periodic sexual receptiveness and fertility of most mammals.
2. Relating to or denoting sexual desire or lust.

Origin:

Derived from the latin 'oestrus' meaning 'frenzy, madness', from the greek 'oistros' meaning 'gadfly, frenzy'.

Examples:

1. The female deer was in estrous and could be seen following the males in the herd.
2. The estrous cycle of a dog lasts about 21 days and is marked by several behavioral and physiological changes.
3. The estrous state of the mare was monitored to determine the optimal time for breeding.
4. The estrous behavior of the female was an indication of her readiness to mate.
5. Her estrous gaze swept over the room, taking in the eligible bachelors with a mixture of desire and wariness.