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.
petroleum, rock oil (mid-14c. in Anglo-French), from Medieval Latin petroleum, from Latin: petra : rock + oleum : oil. ) is a naturally occurring, yellow-to-black liquid found in geological formations beneath the Earth 's surface, which is commonly refined into various types of fuels.etroleum is used in manufacturing a wide variety of materials, and it is estimated that the world consumes about 90 million barrels each day. Concern over the depletion of the earth's finite reserves of oil, and the effect this would have on a society dependent on it, is a concept known as peak oil.