1. See necessary. 2. Essential, inherent, intrinsic refer to that which is in the natural composition of a thing. Essential suggests that which is in the very essence or constitution of a thing: Oxygen and hydrogen are essential in water. Inherent means inborn or fixed from the beginning as a permanent quality or constituent of a thing: properties inherent in iron. Intrinsic implies belonging to the nature of a thing itself, and comprised within it, without regard to external considerations or accidentally added properties: the intrinsic value of diamonds.

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