/pas'pahr tooh"/ ; Fr. /pahs pannrdd tooh"/ , n. , pl. passe-partouts /-toohz"/ ; Fr. /-tooh"/ .
1. something that passes everywhere or provides a universal means of passage.
2. a master key; skeleton key.
3. an ornamental mat for a picture.
4. a method of framing in which a piece of glass is placed over a picture and is affixed to a backing by means of adhesive strips of paper or other material pasted over the edges.
5. paper prepared for this purpose.
[ 1635-45; ]