verb

• (intransitive) To gradually melt, dissolve, or become fluid; to soften from frozen.
  "the ice thaws"
• (impersonal, intransitive) To become sufficiently warm to melt ice and snow, said in reference to the weather.
  "It's beginning to thaw."
• (intransitive, figuratively) To grow gentle or genial.
  "Her anger has thawed."
• (transitive) To gradually cause frozen things (such as earth, snow, ice) to melt, soften, or dissolve.
  "Mor. Miſlike me not for my complexion, / The ſhadowed liuerie of the burniſht ſunne, / To whom I am a neighbour,and neere bred. / Bring me the faireſt creature North-ward borne, / Where Phœbus fire ſcarce thawes the yſicles, / And let vs make inciſion for your loue, / To proue whoſe blood is reddeſt,his or mine."

noun

• (figuratively) A period of relaxation, of reduced reserve, tension, or hostility or of increased friendliness or understanding.