ETYM French enveloppe.
1. A flat rectangular paper container for papers.
2. A natural covering (as by a fluid).
3. Any wrapper or covering.
4. (Geometry) A curve that is tangent to each of a family of curves.
5. The bag containing the gas in a balloon; SYN. gasbag.
6. The maximum operating capability of a system.
In geometry, a curve that touches all the members of a family of lines or curves. For example, a family of three equal circles all touching each other and forming a triangular pattern (like a clover leaf) has two envelopes: a small circle that fits in the space in the middle, and a large circle that encompasses all three circles. + prikaži više

1. One that mails
2. A container for something to be mailed.
3. Something (as an advertisement) sent by mail