Definition of ambrotype in English:

ambrotype

Pronunciation /ˈambrə(ʊ)tʌɪp/

noun

rare, historical US Photography
  • A photograph produced by setting a glass plate with a negative image on it against a dark background.

Origin

Mid 19th century; earliest use found in Fayetteville (North Carolina) Observer. Probably from ἄμβρο- + type, although compare Ambro-.