幻灯
げ
ん
と
う
Meanings
1
Refers to a transparent slide used in a projector, similar to a photographic slide. The term is somewhat dated; modern usage often prefers スライド.
See also: スライド
My grandfather was sorting through old projection slides.
2
magic lantern
Historical device for projecting images, a precursor to the slide projector. Often encountered in historical or literary contexts.
See also: 幻灯機
Magic lanterns were popular in the 19th century.