In chemistry and biology, "matter" is defined as:

1. The stem asks for the most fundamental definition used at the start of this topic. 2. The text states: "Matter is any substance that occupies space and has mass." 3. This definition applies equally to living and non-living material, to charged and uncharged substances, and to solids, liquids, and gases alike. 4. So matter is defined simply as anything occupying space and having mass -- not restricted to living things, charge, or a particular state. _Source: OpenStax Biology Ch 2 "The Chemical Foundation of Life", p.33 §2.1 | Atoms, Isotopes, Ions, and Molecules: The Building Blocks_