early 15c. (Chauliac), "reddish, flushed," especially of the face, especially as a result of indulgence in appetites, from Old French rubicond (14c.) and directly from Latin rubicundus, from rubere "to be red," from ruber "red" (from PIE root *reudh- "red, ruddy"). Related: Rubicundity.
updated on October 16, 2021