What is other than dravya is adravya or non-substance. It is defined as that which cannot be the substratum of anything else and which is necessarily dependent on dravya.
A mere quality of an entity cannot be regarded as adravya. It should be such a quality or property of a substance that it does not become a substrate for another quality and is integrally related to the substance.
For example, jnana? or knowledge is a quality of the jiva, but jnana though inseparably related to the jiva, is not adravya, because it serves as a substrate for its modifications. rupa? or color as a quality is adravya since it is not the substrate for any other qualities and at the same time is inseparable from the substance in which it inheres.
In view of the above, adravya is also defined as that which cannot admit conjunction with another quality.
There are ten fundamental adravyas (as enumerated by Vedanta Desikan )
The terms dravya and adravya are comprehensive in character and mutually exclusive. What is a dravya can never be an adravya and vice-versa.