Definition of ESTRUS. : a regularly recurrent state of sexual excitability during which the female of most mammals will accept the male and is capable of conceiving: heat; also: a single occurrence of this state. See estrus defined for kids.
1. (medicine) any of various liquids sold as medicine (as by a travelling medicine show) but medically worthless. 2. communication (written or spoken) intended to deceive. Familiarity information: SNAKE OIL used as a noun is rare. Dictionary entry details.
Tea tree oil comes from the leaves of an Australian tree called Melaleuca alternifolia. It is an essential oil with a long history of use as a natural remedy for skin ailments and other conditions. Unfortunately, sometimes natural is confused with non-toxic or non-poisonous. Tea tree oil, like many other natural substances, can indeed be poisonous if used in the wrong way, especially if swallowed.