1. A mark or quality, as of distinction, individuality, or authenticity: "Federal courts have a certain cachet which state courts lack" (Christian Science Monitor).
2. A seal on a document, such as a letter.
3. 1. A commemorative design stamped on an envelope to mark a postal or philatelic event.
   2. A motto forming part of a postal cancellation.
4. A kind of wafer capsule formerly used by pharmacists for presenting an unpleasant-tasting drug.

[French, from Old French, from cacher, to press. See cache.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.