/
ˈɛnvələʊp,
ˈɒn-/
n.
- a flat paper container with a sealable flap, used to enclose a letter or document.
- a covering or containing structure or layer.
- Electronics a curve joining the successive peaks of a modulated wave.
- Mathematics a curve or surface tangent to each of a family of curves or surfaces.
Phrase
- push the
(edge of the)
envelope
informal approach or extend the limits of what is possible.
[orig. aviation sl., relating to graphs of aerodynamic performance.]
Etymology
C16 (in the sense ‘enveloping layer’): from Fr. enveloppe, from envelopper ‘envelop’.
