noun
Historical pseudoscience that claimed to determine character and mental faculties from the shape of the skull. Now a domain-specific term used in historical or critical contexts.
19世紀には骨相学が流行した。
Phrenology was popular in the 19th century.
From 骨 (bone) + 相 (physiognomy, aspect) + 学 (study), a calque of English 'phrenology' or its Western origins.