An mirror used to bend an optical path so that it can be made longer than the physical size of the system

A fold mirror that is a "flat", i.e. a plane mirror

(newspapers) Situated in the upper half of the front page of a broadsheet newspaper, and thus more prominent, as the lower half is not usually visible when the folded newspaper is displayed for sale.

(slang) Banknotes, paper money.

(idiomatic) To make or become more compact by folding. / (idiomatic) To go out of business.

An optical system in which prisms and/or mirrors are used to reduce the overall physical length of the system.

present participle of fold up

simple past tense and past participle of fold up

Having been folded; having many folds.

Synonym of epicanthus