Source : Webster's Revised Unabridged Dictionary (1913)

Shallow \Shal"low\, a. [Compar. {Shallower}; superl.
   {Shallowest}.] [OE. schalowe, probably originally, sloping or
   shelving; cf. Icel. skj[=a]lgr wry, squinting, AS. sceolh, D.
   & G. scheel, OHG. schelah. Cf. {Shelve} to slope, {Shoal}
   shallow.]
   1. Not deep; having little depth; shoal. ``Shallow brooks,
      and rivers wide.'' --Milton.

   2. Not deep in tone. [R.]

            The sound perfecter and not so shallow and jarring.
                                                  --Bacon.

   3. Not intellectually deep; not profound; not penetrating
      deeply; simple; not wise or knowing; ignorant;
      superficial; as, a shallow mind; shallow learning.

            The king was neither so shallow, nor so ill
            advertised, as not to perceive the intention of the
            French king.                          --Bacon.

            Deep versed in books, and shallow in himself.
                                                  --Milton.

Shallow \Shal"low\, n.
   1. A place in a body of water where the water is not deep; a
      shoal; a flat; a shelf.

            A swift stream is not heard in the channel, but upon
            shallows of gravel.                   --Bacon.

            Dashed on the shallows of the moving sand. --Dryden.

   2. (Zo["o]l.) The rudd. [Prov. Eng.]

Shallow \Shal"low\, v. t.
   To make shallow. --Sir T. Browne.

Shallow \Shal"low\, v. i.
   To become shallow, as water.

Source : WordNet®

shallow
     adj 1: lacking physical depth; having little spatial extension
            downward or inward from an outer surface or backward
            or outward from a center; "shallow water"; "a shallow
            dish"; "a shallow cut"; "a shallow closet";
            "established a shallow beachhead"; "hit the ball to
            shallow left field" [ant: {deep}]
     2: not deep or strong; not affecting one deeply; "shallow
        breathing"; "a night of shallow fretful sleep"; "in a
        shallow trance" [ant: {deep}]
     3: lacking depth of intellect or knowledge; concerned only with
        what is obvious; "shallow people"; "his arguments seemed
        shallow and tedious"

shallow
     n : a stretch of shallow water [syn: {shoal}]

shallow
     v 1: make shallow; "The silt shallowed the canal" [syn: {shoal}]
     2: become shallow; "the lake shallowed over time" [syn: {shoal}]