late 14c., "art of judging characters from facial features," from Old French phizonomie and directly from Late Latin physiognomia, from Greek physiognomia "the judging of a person's nature by his features," from physio- (see physio-) + gnōmōn (genitive gnōmōnos) "judge, indicator," from PIE root *gno- "to know." Meaning "face, countenance, features" is from c. 1400. Related: Physiognomical.
