an oil having the odor or flavor of the plant from which it comes; used in perfume and flavorings
an interface forming the boundary between the non-miscible liquids oil and water
absolutely necessary; vitally necessary
basic and fundamental
of the greatest importance
anything indispensable
defining rights and duties as opposed to giving the rules by which rights and duties are established
a slippery or viscous liquid or liquefiable substance not miscible with water
