Meaning of envelope

Definition of envelope

(noun) a flat (usually rectangular) container for a letter, thin package, etc.
any wrapper or covering
a curve that is tangent to each of a family of curves
a natural covering (as by a fluid); "the spacecraft detected an envelope of gas around the comet"
the maximum operating capability of a system (especially an aircraft); "test pilots try to push the envelope"
the bag containing the gas in a balloon

Other information on envelope

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