Substance definition

(1) That which has mass and occupies space

"An atom is the smallest indivisible unit of matter"

(2) The idea that is intended

"What is the meaning of this proverb?"

(3) The choicest or most essential or most vital part of some idea or experience

"The gist of the prosecutor's argument"

"The heart and soul of the Republican Party"

"The nub of the story"

(4) What a communication that is about something is about

(5) Considerable capital (wealth or income)

"He is a man of means"

(6) The stuff of which an object consists