1. [n]  the syllable naming the fifth (dominant) note of any musical scale in solmization
2. [n]  (Greek mythology) ancient Roman god; personification of the sun; counterpart of Greek Helios
3. [n]  a colloid that has a continuous liquid phase in which a solid is suspended in a liquid

1. \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.
   

2. \Sol\, n. [L.]
   1. The sun.
   2. (Alchem.) Gold; -- so called from its brilliancy, color,
      and value. --Chaucer.
   

3. \Sol\, n. [It.] (Mus.)
      (a) A syllable applied in solmization to the note G, or to
          the fifth tone of any diatonic scale.
      (b) The tone itself.
   

4. \Sol\, n. [See {Sou}.]
   1. A sou.
   2. A silver and gold coin of Peru. The silver sol is the unit
      of value, and is worth about 68 cents.
   

1. Simulation Oriented Language.

2. Second-Order lambda-calculus.

3. Semantic Operating Language. Language for manipulating semantic networks for building cognitive models, particularly for natural language understanding. "Explorations in Cognition", D.A. Norman et al, W.H. Freeman 1974.

4. Shit Outta Luck.