The Collaborative International Dictionary of English v.0.48:

Liquid \Liq"uid\ (l[i^]k"w[i^]d), a. [L. liquidus, fr. liquere
   to be fluid or liquid; cf. Skr. r[imac] to ooze, drop,
   l[imac] to melt.]
   1. Flowing freely like water; fluid; not solid.
      [1913 Webster]

            Yea, though he go upon the plane and liquid water
            which will receive no step.           --Tyndale.
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   2. (Physics) Being in such a state that the component
      molecules move freely among themselves, but have a
      definite volume changing only slightly with changes of
      pressure, and do not tend to separate from each other as
      the particles of gases and vapors do when the volume of
      the container is increased; neither solid nor gaseous; as,
      liquid mercury, in distinction from mercury solidified or
      in a state of vapor.

   Note: Liquid substances may form a definite interface with
         gases, whereas the molecules of different gases freely
         intermingle with each other.
         [1913 Webster +PJC ]

   3. Flowing or sounding smoothly or without abrupt transitions
      or harsh tones. "Liquid melody." --Crashaw.
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   4. Pronounced without any jar or harshness; smooth; as, l and
      r are liquid letters.
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   5. Fluid and transparent; as, the liquid air.
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   6. Clear; definite in terms or amount. [Obs.] "Though the
      debt should be entirely liquid." --Ayliffe.

   7. (Finance) In cash or readily convertible into cash without
      loss of principle; -- said of assets, such as bank
      accounts, or short-term bonds tradable on a major stock
      exchange.
      [PJC]

   Liquid glass. See Soluble glass, under Glass.
      [1913 Webster]