envelope
Concise Oxford English Dictionary © 2008 Oxford University Press:
envelope /ˈɛnvələʊp, ˈɒn-/
▶noun
- 1 a flat paper container with a sealable flap, used to enclose a letter or document.
- 2 a covering or containing structure or layer.
- 3 Electronics a curve joining the successive peaks of a modulated wave.
- 4 Mathematics a curve or surface tangent to each of a family of curves or surfaces.
– phrases
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.]
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.]
– origin C16 (in the sense ‘enveloping layer’): from Fr. enveloppe, from envelopper ‘envelop’.
'envelope' also found in these Oxford entries:
address
- atmosphere
- corona
- cover
- enclose
- enclosure
- first-day cover
- flight envelope
- involucre
- jacket
- Jiffy bag
- photosphere
- plain
- pochette
- postcard
- sae
- SASE
- self-addressed
- self-sealing
- window
