Source : Webster's Revised Unabridged Dictionary (1913)

Substance \Sub"stance\, v. t.
   To furnish or endow with substance; to supply property to; to
   make rich. [Obs.]

Substance \Sub"stance\, n. [F., fr. L. substantia, fr. substare
   to be under or present, to stand firm; sub under + stare to
   stand. See {Stand}.]
   1. That which underlies all outward manifestations;
      substratum; the permanent subject or cause of phenomena,
      whether material or spiritual; that in which properties
      inhere; that which is real, in distinction from that which
      is apparent; the abiding part of any existence, in
      distinction from any accident; that which constitutes
      anything what it is; real or existing essence.

            These cooks, how they stamp, and strain, and grind,
            And turn substance into accident!     --Chaucer.

            Heroic virtue did his actions guide, And he the
            substance, not the appearance, chose. --Dryden.

   2. The most important element in any existence; the
      characteristic and essential components of anything; the
      main part; essential import; purport.

            This edition is the same in substance with the
            Latin.                                --Bp. Burnet.

            It is insolent in words, in manner; but in substance
            it is not only insulting, but alarming. --Burke.

   3. Body; matter; material of which a thing is made; hence,
      substantiality; solidity; firmness; as, the substance of
      which a garment is made; some textile fabrics have little
      substance.

   4. Material possessions; estate; property; resources.

            And there wasted his substance with riotous living.
                                                  --Luke xv. 13.

            Thy substance, valued at the highest rate, Can not
            amount unto a hundred marks.          --Shak.

            We are destroying many thousand lives, and
            exhausting our substance, but not for our own
            interest.                             --Swift.

   5. (Theol.) Same as {Hypostasis}, 2.

Source : WordNet®

substance
     n 1: that which has mass and occupies space; "an atom is the
          smallest indivisible unit of matter" [syn: {matter}]
     2: the stuff of which an object consists
     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" [syn: {kernel}, {core}, {center}, {essence},
         {gist}, {heart}, {heart and soul}, {inwardness}, {marrow},
         {meat}, {nub}, {pith}, {sum}, {nitty-gritty}]
     4: the idea that is intended; "What is the meaning of this
        proverb?" [syn: {meaning}]
     5: considerable capital (wealth or income); "he is a man of
        means" [syn: {means}]
     6: what a communication that is about something is about [syn:
        {message}, {content}, {subject matter}]