Lewis & Short

exustĭo, ōnis, f. [exuro].

  1. I. A burning up, a conflagration: eluviones exustionesque terrarum, Cic. Rep. 6, 21, 23: ignis, Vulg. Isa. 64, 2: quorum finis exustio est, Hier. in Isa. 3, 7, 4.
    Trop., Plin. 18, 1, 1, § 5.
  2. II. A burning, scorching: solis, Plin. 17, 24, 37, § 223.