1.That by which one can pass anywhere; a safe-conduct. (Obs.)
2.A master key; a latchkey.
3.A light picture frame or mat of cardboard, wood, or the like, usually put between the picture and the glass, and sometimes serving for several pictures.
4.A strip of adhesive paper or gummed tape used to mount a picture between a piece of glass and a backing.
5.The method of mounting a picture between a piece of glass and a backing, using a passe-partout (4).
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