- envelope - a flat rectangular paper container for papers
--1 is a kind of container
--1 has particulars: window envelope- envelope - any wrapper or covering
--2 is a kind of wrapping, wrap, wrapper
- envelope - a curve that is tangent to each of a family of curves
--3 is a kind of curve, curved shape
- envelope - a natural covering (as by a fluid); "the spacecraft detected an envelope of gas around the comet"
--4 is a kind of covering, natural covering, cover
- envelope - the maximum operating capability of a system; "test pilots try to push the envelope"
--5 is a kind of operating capability, performance capability
- envelope, gasbag - the bag containing the gas in a balloon
--6 is a kind of bag
--6 is a part of balloon - envelope - any wrapper or covering