The Collaborative International Dictionary of English v.0.48:

Deliquium \De*liq"ui*um\, n. [L. See Deliquiate.]
   1. (Chem.) A melting or dissolution in the air, or in a moist
      place; a liquid condition; as, a salt falls into a
      deliquium. [R.]
      [1913 Webster]

   2. A sinking away; a swooning. [Obs.] --Bacon.
      [1913 Webster]

   3. A melting or maudlin mood. --Carlyle.
      [1913 Webster]

WordNet (r) 3.0 (2006):

deliquium
    n 1: a spontaneous loss of consciousness caused by insufficient
         blood to the brain [syn: faint, swoon, syncope,
         deliquium]