The Collaborative International Dictionary of English v.0.48:

thaw \thaw\ (th[add]), v. i. [imp. & p. p. Thawed (th[add]d);
   p. pr. & vb. n. Thawing.] [AS. [thorn][=a]wian,
   [thorn][=a]wan; akin to D. dovijen, G. tauen, thauen (cf.
   also verdauen to digest, OHG. douwen, firdouwen), Icel.
   [thorn]eyja, Sw. t["o]a, Dan. t["o]e, and perhaps to Gr.
   th`kein to melt. [root]56.]
   1. To melt, dissolve, or become fluid; to soften; -- said of
      that which is frozen; as, the ice thaws.
      [1913 Webster]

   2. To become so warm as to melt ice and snow; -- said in
      reference to the weather, and used impersonally.
      [1913 Webster]

   3. Fig.: To grow gentle or genial. Compare cold[4], a. and
      hard[6], a.
      [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

thawed
    adj 1: no longer frozen solid; "the thawed ice was treacherous"
    2: no longer frozen; "the thawed ground was muddy"