What is the meaning of Substance?

Physical matter; material.

A form of matter that has constant chemical composition and characteristic properties.

The essential part of anything; the most vital part.

Substantiality; solidity; firmness.

Material possessions; estate; property; resources.

Drugs (illegal narcotics)

Ousia, essence; underlying reality or hypostasis in the philosophical sense.

To give substance to; to make real or substantial.

substance

essence

most essential; substantial part

existence

Source: wiktionary.org