evanescing

from The Collaborative International Dictionary of English v.0.48

Evanesce \Ev`a*nesce"\ ([e^]v`[.a]*n[e^]s"), v. i. [imp. & p. p.
   {Evanesced} ([e^]v`[.a]*n[e^]st"); p. pr. & vb. n.
   {Evanescing}. ([e^]v`[.a]*n[e^]s"s[i^]ng).] [L. evanescere; e
   out + vanescere to vanish, fr. vanus empty, vain. See {Vain},
   and cf. {Evanish}.]
   To vanish away; to become dissipated and disappear, like
   vapor.
   [1913 Webster]

         I believe him to have evanesced or evaporated. --De
                                                  Quincey.
   [1913 Webster]