noun
small western mirror with mercury added to the glass (Edo period)
Historical term for a type of mirror produced during the Edo period. The name literally means 'conceited mirror' or 'self-admiring mirror', possibly because the mercury backing gave a clearer reflection, encouraging vanity.
See also: 和鏡
江戸時代の自惚れ鏡は、ガラスに水銀を塗って作られた。
The self-admiring mirror of the Edo period was made by applying mercury to glass.
博物館で珍しい自惚れ鏡を見た。
I saw a rare self-admiring mirror at the museum.
和鏡 refers to traditional Japanese mirrors (usually bronze), while 自惚れ鏡 is a specific type of western-style mirror from the Edo period.
Compound of 自惚れ (うぬぼれ, 'conceit, self-admiration') and 鏡 (かがみ, 'mirror'). The name likely arose from the improved clarity of the mercury-backed glass, which made one's reflection more flattering.