1
: a flat usually paper container (as for a letter)
2
: something that envelops : wrapper
the envelope of air around the earth
3
a
: the outer covering of an aerostat
b
: the bag containing the gas in a balloon or airship
4
a
: a natural enclosing covering (such as a membrane, shell, or integument)
b
: a lipoprotein unit membrane that forms the outer layer of some virions
5
a
: a curve tangent to each of a family of curves
b
: a surface tangent to each of a family of surfaces
6
: a set of performance limits (as of an aircraft) that may not be safely exceeded
also : the set of operating parameters that exists within these limits
7
: a conventionally accepted limit
new computers that push the envelope
How do you pronounce envelope?: Usage Guide

The \ˈen-\ and \ˈän-\ pronunciations are used with about equal frequency, and both are fully acceptable, though the \ˈän-\ version is sometimes decried as "pseudo-French." Actually \ˈän-\ is exactly what one would expect to hear when a French word like entrepreneur is becoming anglicized. Envelope, however, has been in English for nearly 300 years, plenty of time for it to become completely anglicized and for both of its pronunciations to win respectability.

Examples of envelope in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Officials said McIntosh used social media to sell the sheets and envelopes, with customers paying her to mail the documents to inmates at correctional facilities, the prosecutors said. Megan Forrester, ABC News, 18 Mar. 2025 In the brief clip, Uchis blows on a shelf full of candles while rocking rollers in her hair, sparking flames as if by magic, before grabbing an envelope with the album’s title on it. Gil Kaufman, Billboard, 17 Mar. 2025 For now, the blue envelopes are available at the Portage Township offices, Portage Police and the Porter County Sheriff’s Office. Jim Woods, Chicago Tribune, 16 Mar. 2025 Abe ended up slipping the envelope under his leg in footage widely shared by Iranian state media to this day. arkansasonline.com, 13 Mar. 2025 See All Example Sentences for envelope

Word History

First Known Use

circa 1714, in the meaning defined at sense 1

Time Traveler
The first known use of envelope was circa 1714

Browse Nearby Words

Cite this Entry

“Envelope.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/envelope. Accessed 30 Mar. 2025.

Kids Definition

1
: a flat usually paper container (as for a letter)
2
: something that envelops
3
: the bag containing the gas in a balloon or airship
4
: a natural enclosing covering (as a membrane)

Medical Definition

: a natural enclosing covering (as a membrane or integument)
especially : a lipoprotein unit membrane that forms the outer layer of some virions and surrounds the viral capsid
These glycoprotein complexes, swept up by the budding virus as it acquires its envelope, are crucial to HIV's ability to infect new cells. William A. Haseltine et al., Scientific American
Last Updated: - Updated example sentences
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