Meaning of FINDER in English

FINDER

add. ·noun a slide ruled in squares, so as to assist in locating particular points in the field of vision.

2. finder ·noun one who, or that which, finds; specifically (astron.), a small telescope of low power and large field of view, attached to a larger telescope, for the purpose of finding an object more readily.

Webster English vocab.      Английский словарь Webster.