Source : Webster's Revised Unabridged Dictionary (1913)

Sound \Sound\, v. t. [imp. & p. p. {Sounded}; p. pr. & vb. n.
   {Sounding}.] [F. sonder; cf. AS. sundgyrd a sounding rod,
   sundline a sounding line (see {Sound} a narrow passage of
   water).]
   1. To measure the depth of; to fathom; especially, to
      ascertain the depth of by means of a line and plummet.

   2. Fig.: To ascertain, or try to ascertain, the thoughts,
      motives, and purposes of (a person); to examine; to try;
      to test; to probe.

            I was in jest, And by that offer meant to sound your
            breast.                               --Dryden.

            I've sounded my Numidians man by man. --Addison.

   3. (Med.) To explore, as the bladder or urethra, with a
      sound; to examine with a sound; also, to examine by
      auscultation or percussion; as, to sound a patient.

Sounding \Sound"ing\, a.
   Making or emitting sound; hence, sonorous; as, sounding
   words. --Dryden.

Sounding \Sound"ing\, n.
   1. The act of one who, or that which, sounds (in any of the
      senses of the several verbs).

   2. (Naut.) [From {Sound} to fathom.]
      (a) measurement by sounding; also, the depth so
          ascertained.
      (b) Any place or part of the ocean, or other water, where
          a sounding line will reach the bottom; -- usually in
          the plural.
      (c) The sand, shells, or the like, that are brought up by
          the sounding lead when it has touched bottom.

   {Sounding lead}, the plummet at the end of a sounding line.
      

   {Sounding line}, a line having a plummet at the end, used in
      making soundings.

   {Sounding post} (Mus.), a small post in a violin,
      violoncello, or similar instrument, set under the bridge
      as a support, for propagating the sounds to the body of
      the instrument; -- called also {sound post}.

   {Sounding rod} (Naut.), a rod used to ascertain the depth of
      water in a ship's hold.

   {In soundings}, within the eighty-fathom line. --Ham. Nav.
      Encyc.

Source : WordNet®

sounding
     adj 1: appearing to be as specified; usually used as combining
            forms; "left their clothes dirty looking"; "a most
            disagreeable looking character"; "angry-looking";
            "liquid-looking"; "severe-looking policemen on noble
            horses"; "fine-sounding phrases"; "taken in by
            high-sounding talk" [syn: {looking}]
     2: having volume or depth; "sounding brass and a tinkling
        cymbal"; "the sounding cataract haunted me like a
        passion"- Wordsworth
     3: making or having a sound as specified; used as a combining
        form; "harsh-sounding"

sounding
     n 1: a measure of the depth of water taken by sounding
     2: the act of measuring depth of water (usually with a sounding
        line)