The Collaborative International Dictionary of English v.0.48:

Sol \Sol\ Sole \Sole\, n. [From hydrosol an aqueous colloidal
   solution, confused with G. sole, soole, salt water from which
   salt is obtained.] (Chem.)
   A fluid mixture of a colloid and a liquid; a liquid colloidal
   solution or suspension.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Sole \Sole\ (s[=o]l), n. [AS. sole, fr. L. soolea (or rather an
   assumed L. sola), akin to solumround, soil, sole of the foot.
   Cf. Exile, Saloon, Soil earth, Sole the fish.]
   1. The bottom of the foot; hence, also, rarely, the foot
      itself.
      [1913 Webster]

            The dove found no rest for the sole of her foot.
                                                  --Gen. viii.
                                                  9.
      [1913 Webster]

            Hast wandered through the world now long a day,
            Yet ceasest not thy weary soles to lead. --Spenser.
      [1913 Webster]

   2. The bottom of a shoe or boot, or the piece of leather
      which constitutes the bottom.
      [1913 Webster]

            The "caliga" was a military shoe, with a very thick
            sole, tied above the instep.          --Arbuthnot.
      [1913 Webster]

   3. The bottom or lower part of anything, or that on which
      anything rests in standing. Specifially:
      (a) (Agric.) The bottom of the body of a plow; -- called
          also slade; also, the bottom of a furrow.
      (b) (Far.) The horny substance under a horse's foot, which
          protects the more tender parts.
      (c) (Fort.) The bottom of an embrasure.
      (d) (Naut.) A piece of timber attached to the lower part
          of the rudder, to make it even with the false keel.
          --Totten.
      (e) (Mining) The seat or bottom of a mine; -- applied to
          horizontal veins or lodes.
          [1913 Webster]

   Sole leather, thick, strong, used for making the soles of
      boots and shoes, and for other purposes.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sole \Sole\, n. [F. sole, L. solea; -- so named from its flat
   shape. See Sole of the foot.] (Zool.)
   (a) Any one of several species of flatfishes of the genus
       Solea and allied genera of the family Soleidae,
       especially the common European species (Solea
       vulgaris), which is a valuable food fish.
   (b) Any one of several American flounders somewhat resembling
       the true sole in form or quality, as the California sole
       (Lepidopsetta bilineata), the long-finned sole
       (Glyptocephalus zachirus), and other species.
       [1913 Webster]

   Lemon, or French, sole (Zool.), a European species of
      sole (Solea pegusa).

   Smooth sole (Zool.), the megrim.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sole \Sole\, v. t. [imp. & p. p. Soled; p. pr. & vb. n.
   Soling.]
   To furnish with a sole; as, to sole a shoe.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sole \Sole\, a. [L. solus, or OF. sol, F. seul (fr. L. solus;
   cf. L. sollus whole, entire. Cf. Desolate, Solemn,
   Solo, Sullen.]
   1. Being or acting without another; single; individual; only.
      "The sole son of my queen." --Shak.
      [1913 Webster]

            He, be sure . . . first and last will reign
            Sole king.                            --Milton.
      [1913 Webster]

   2. (Law) Single; unmarried; as, a feme sole.
      [1913 Webster]

   Corporation sole. See the Note under Corporation.
      [1913 Webster]

   Syn: Single; individual; only; alone; solitary.
        [1913 Webster]

WordNet (r) 3.0 (2006):

sole
    adj 1: not divided or shared with others; "they have exclusive
           use of the machine"; "sole rights of publication" [syn:
           exclusive, sole(a)]
    2: being the only one; single and isolated from others; "the
       lone doctor in the entire county"; "a lonesome pine"; "an
       only child"; "the sole heir"; "the sole example"; "a solitary
       instance of cowardice"; "a solitary speck in the sky" [syn:
       lone(a), lonesome(a), only(a), sole(a),
       solitary(a)]
    n 1: the underside of footwear or a golf club
    2: lean flesh of any of several flatfish [syn: sole, fillet
       of sole]
    3: the underside of the foot
    4: right-eyed flatfish; many are valued as food; most common in
       warm seas especially European
    v 1: put a new sole on; "sole the shoes" [syn: sole, resole]

Moby Thesaurus II by Grady Ward, 1.0:

101 Moby Thesaurus words for "sole":
   a certain, absolute, alone, an, any, any one, arch, atomic,
   azygous, bachelorlike, base, baseboard, basement, celibate,
   chassis, clubfoot, dado, digit, dog, either, exclusive, extremity,
   fetlock, first and last, foot, footing, forefoot, forepaw,
   foundation, frame, harefoot, heel, hoof, husbandless, impair,
   individual, indivisible, instep, integral, irreducible, keel, lone,
   maiden, maidenly, monadic, monistic, mopboard, nadir, odd,
   old-maidish, one, one and only, only, only-begotten, pad,
   particular, pastern, patte, paw, pedal extremity, pedes, personal,
   pes, pied, pug, separate, shoemold, simple, single, singular,
   solid, solitary, solo, spinsterish, spinsterlike, spinsterly,
   splayfoot, spouseless, toe, tootsy, trotter, unanalyzable,
   underneath, underside, undivided, unexampled, ungula, uniform,
   unique, unitary, unmarried, unpaired, unrepeatable, unrepeated,
   unshared, unwed, unwedded, virgin, virginal, wainscot, whole



Bouvier's Law Dictionary, Revised 6th Ed (1856):

SOLE. Alone, single; used in contradistinction to joint or married. A sole
tenant, therefore, is one who holds lands in his own right, without being
joined with any other. A feme sole is a single woman; a sole corporation is
one composed of only one natural person.