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.
Mineral oil (petroleum). This is a moisturizing agent (used to lock moisture against skin) and is also part of the formulation for perfume in cosmetics. It is a byproduct of the distillation of gasoline from crude oil. Mineral oil is the leftover liquid.