The Collaborative International Dictionary of English v.0.48:

Profound \Pro*found"\, n.
   1. The deep; the sea; the ocean.
      [1913 Webster]

            God in the fathomless profound
            Hath all this choice commanders drowned. --Sandys.
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   2. An abyss. --Milton.
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The Collaborative International Dictionary of English v.0.48:

Profound \Pro*found"\, v. t.
   To cause to sink deeply; to cause to dive or penetrate far
   down. [Obs.] --Sir T. Browne.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Profound \Pro*found"\, v. i.
   To dive deeply; to penetrate. [Obs.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Profound \Pro*found"\, a. [F. profond, L. profundus; pro before,
   forward + fundus the bottom. See Found to establish,
   Bottom lowest part.]
   1. Descending far below the surface; opening or reaching to a
      great depth; deep. "A gulf profound." --Milton.
      [1913 Webster]

   2. Intellectually deep; entering far into subjects; reaching
      to the bottom of a matter, or of a branch of learning;
      thorough; as, a profound investigation or treatise; a
      profound scholar; profound wisdom.
      [1913 Webster]

   3. Characterized by intensity; deeply felt; pervading;
      overmastering; far-reaching; strongly impressed; as, a
      profound sleep. "Profound sciatica." --Shak.
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            Of the profound corruption of this class there can
            be no doubt.                          --Milman.
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   4. Bending low, exhibiting or expressing deep humility;
      lowly; submissive; as, a profound bow.
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            What humble gestures! What profound reverence!
                                                  --Duppa.
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WordNet (r) 3.0 (2006):

profound
    adj 1: showing intellectual penetration or emotional depth; "the
           differences are profound"; "a profound insight"; "a
           profound book"; "a profound mind"; "profound contempt";
           "profound regret" [ant: superficial]
    2: of the greatest intensity; complete; "a profound silence"; "a
       state of profound shock"
    3: far-reaching and thoroughgoing in effect especially on the
       nature of something; "the fundamental revolution in human
       values that has occurred"; "the book underwent fundamental
       changes"; "committed the fundamental error of confusing
       spending with extravagance"; "profound social changes" [syn:
       fundamental, profound]
    4: coming from deep within one; "a profound sigh"
    5: (of sleep) deep and complete; "a heavy sleep"; "fell into a
       profound sleep"; "a sound sleeper"; "deep wakeless sleep"
       [syn: heavy, profound, sound, wakeless]
    6: situated at or extending to great depth; too deep to have
       been sounded or plumbed; "the profound depths of the sea";
       "the dark unfathomed caves of ocean"-Thomas Gray; "unplumbed
       depths of the sea"; "remote and unsounded caverns" [syn:
       profound, unfathomed, unplumbed, unsounded]

Moby Thesaurus II by Grady Ward, 1.0:

174 Moby Thesaurus words for "profound":
   Atlantean, Brobdingnagian, Cyclopean, Gargantuan, Herculean,
   Homeric, absolute, absorbing, abstract, abstruse, abysmal, acute,
   analytical, ankle-deep, arcane, arrant, astronomic, astute, awful,
   broad-minded, cabbalistic, civilized, classical, colossal,
   complete, consummate, crass, cryptic, cultivated, cultured,
   decided, deep, deep-cut, deep-down, deep-engraven, deep-felt,
   deep-fixed, deep-laid, deep-lying, deep-reaching, deep-rooted,
   deep-seated, deep-set, deep-settled, deep-sinking, deep-sunk,
   deep-sunken, deepgoing, deepish, deepsome, definitive, discerning,
   downright, educated, egregious, elephantine, encyclopedic,
   enigmatic, enormous, epic, erudite, esoteric, extreme, flagrant,
   giant, giantlike, gigantic, glaring, great, gross, hard, heartfelt,
   heavy, hermetic, heroic, hidden, homefelt, huge, immense,
   incomprehensible, indecipherable, indelible, infinite, informed,
   inscrutable, insightful, intellectual, intense, intolerable,
   intricate, involved, jumbo, keen, knee-deep, knotty, knowing,
   knowledgeable, learned, lettered, literate, mammoth, mighty,
   monster, monstrous, monumental, mountainous, mysterious,
   mystifying, obscure, occult, out-and-out, outright, overpowering,
   overwhelming, pansophic, penetrating, perfect, pervading, piercing,
   poignant, polyhistoric, polymath, polymathic, positive, precious,
   prodigious, pronounced, proper, puzzling, rank, recondite, regular,
   sagacious, sage, sapient, scholarly, scholastic, secret, sharp,
   shattering, shocking, sincere, stark, stark-staring, studious,
   stupendous, subtle, superlative, surpassing, terrible, the veriest,
   thorough, thoroughgoing, titanic, total, towering, transcendental,
   tremendous, tricky, unbearable, unconscionable, undeniable,
   unequivocal, unfathomable, unmitigated, unqualified, unrelieved,
   unspoiled, utter, vast, well-informed, well-read, wise,
   wise as Solomon