A person who practices physiognomy, the art of judging character from facial features. The term is somewhat specialized and may be encountered in historical or literary contexts.
See also: 人相見
He claimed that as a physiognomist, he could read a person's character from their face.
Compound of 観 (kan, 'observe') + 相 (sō, 'appearance') + 家 (ka, 'specialist'). The exact historical derivation is uncertain, but the term follows a standard pattern for naming practitioners of a field.