Definitions
1.nounA seal, as of a letter.
2.nounA special characteristic or quality; prestige."I remember when this diner was a quiet hangout, but lately it seems to be losing its cachet."
3.nounA commemorative stamped design or inscription on an envelope, other than a cancellation or pre-printed postage.
4.nounA sealed envelope containing an item whose price is being negotiated.
5.nounA capsule containing a pharmaceutical preparation.
6.nounA hidden location from which one can observe birds while remaining unseen.