Lewis & Short

irrŭbesco (inr-), bŭi, 3,

  1. I. v. inch. n. [in-rubesco], to grow red, be reddened: nec sanguine ferrum irrubuit, Stat. Th. 6, 231; 9, 647: haemachates sanguineis maculis irrubescit, Sol. 5, 27.
  2. II. To throw a red light upon a thing: tuis ut mihi vultibus ignis irrubuit, Stat. S. 5, 3, 32.