ADJECTIVE (2)

1. (of a substance) capable of being dissolved in some solvent (usually water);

2. susceptible of solution or of being solved or explained;
- Example: "the puzzle is soluble"

The Collaborative International Dictionary of English v.0.48:

Soluble \Sol"u*ble\, a. [L. solubilis, fr. solvere, solutum, to
   loosen, to dissolve: cf. F. soluble. See Solve, and cf.
   Solvable.]
   1. Susceptible of being dissolved in a fluid; capable of
      solution; as, some substances are soluble in alcohol which
      are not soluble in water.
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            Sugar is . . . soluble in water and fusible in fire.
                                                  --Arbuthnot.
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   2. Susceptible of being solved; as, a soluble algebraic
      problem; susceptible of being disentangled, unraveled, or
      explained; as, the mystery is perhaps soluble. "More
      soluble is this knot." --Tennyson.
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   3. Relaxed; open or readily opened. [R.] "The bowels must be
      kept soluble." --Dunglison.
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   Soluble glass. (Chem.) See under Glass.
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