1. (n.) That which forms the basis of anything; underlying principle; a concept or mental entity conceived or treated as an existing being or thing.

2. (n.) Substance; subsistence; essence; person; personality; -- used by the early theologians to denote any one of the three subdivisions of the Godhead, the Father, Son, and Holy Spirit.

3. (n.) Principle; an element; -- used by the alchemists in speaking of salt, sulphur, and mercury, which they considered as the three principles of all material bodies.

4. (n.) That which is deposited at the bottom of a fluid; sediment.

abstract noun adherent noun air atom atomic particles axiom brute matter building block center chemical element collective noun common noun component constituent core earth element elementary particle elementary unit elixir essence essential fire flower focus fundamental fundamental particle gerund gist gravamen heart hyle inner essence kernel marrow material material world materiality matter meat molecule monad natural world nature nominal noun noun phrase nub nucleus nuts and bolts physical world pith plenum postulate principle pronoun proper noun quid quiddity quintessence quotation noun sap soul spirit stuff substance substantive substratum the four elements the nitty-gritty unit of being water