envelope

[ en-vuh-lohp, ahn- ]

/ ˈɛn vəˌloʊp, ˈɑn- /

SEE MORE SYNONYMS FOR envelope ON THESAURUS.COM

noun

a flat paper container, as for a letter or thin package, usually having a gummed flap or other means of closure.

something that envelops; a wrapper, integument, or surrounding cover.

Biology. a surrounding or enclosing structure, as a corolla or an outer membrane.

Geometry. a curve or surface tangent to each member of a set of curves or surfaces.

Radio. (of a modulated carrier wave) a curve connecting the peaks of a graph of the instantaneous value of the electric or magnetic component of the carrier wave as a function of time.

the fabric structure enclosing the gasbag of an aerostat.

the gasbag itself.

Electronics. the airtight glass or metal housing of a vacuum tube.

the technical limits within which an aircraft or electronic system may be safely operated.

Nearby words

enunciation, enure, enuresis, env., envelop, envelope, envelope chemise, envelopment, envenom, envenomation, enver pasha

Idioms

push the envelope, to stretch established limits, as in technological advance or social innovation.

Also envelop.

Origin of envelope

1700–10; < French enveloppe, derivative of envelopper to envelop

Can be confused

envelop envelope

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for push the envelope

envelope

/ (ˈɛnvəˌləʊp, ˈɒn-) /

noun

a flat covering of paper, usually rectangular in shape and with a flap that can be folded over and sealed, used to enclose a letter, etc

any covering or wrapper

biology any enclosing structure, such as a membrane, shell, or skin

the bag enclosing the gas in a balloon

maths a curve or surface that is tangent to each one of a group of curves or surfaces

electronics the sealed glass or metal housing of a valve, electric light, etc

telecomm the outer shape of a modulated wave, formed by the peaks of successive cycles of the carrier wave

push the envelope informal to push the boundaries of what is possible

Word Origin for envelope

C18: from French enveloppe, from envelopper to wrap around; see envelop; sense 8 from aeronautics jargon, referring to graphs of aircraft performance

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for push the envelope

envelope

[ ĕn′və-lōp′, ŏn′- ]

n.

An enclosing structure or cover, such as a membrane or the outer coat of a virus.

Idioms and Phrases with push the envelope

push the envelope

Exceed the limits of what is normally done, be innovative, as in They are pushing the envelope in using only new fabrics for winter clothing. This idiom comes from aviation, the envelope alluding to the technical limits of a plane's performance, which, on a graph, appear as a rising slope as limits of speed and stress are approached and falls off when the capacity is exceeded and the pilot loses control; safety lies within these limits, or envelope, and exceeding them exposes pilot and plane to risk. [Slang; late 1960s]