# envelope

> English word · Noun · IPA /ˈɛnvələʊp/ · frequency rank #8,786

## Definitions
1. A paper or cardboard wrapper used to enclose small, flat items, especially letters, for mailing.
2. Something that envelops; a wrapping.
3. A bag containing the lifting gas of a balloon or airship; fabric that encloses the gas-bags of an airship.
4. A mathematical curve, surface, or higher-dimensional object that is the tangent to a given family of lines, curves, surfaces, or higher-dimensional objects.
5. A curve that bounds another curve or set of curves, as the modulation envelope of an amplitude-modulated carrier wave in electronics.
6. The shape of a sound, which may be controlled by a synthesizer or sampler.
7. The information used for routing a message that is transmitted with the message but not part of its contents.
8. An enclosing structure or cover, such as a membrane; a space between two membranes
9. The set of limitations within which a technological system can perform safely and effectively.
10. The nebulous covering of the head or nucleus of a comet; a coma.
11. An earthwork in the form of a single parapet or a small rampart, sometimes raised in the ditch and sometimes beyond it.

## Etymology
PIE word
 *h₁én
From French enveloppe. The engineering sense is derived from flight envelope. The verb is from the noun.

## Easily confused with
- **enveloped** (https://plainspell.com/en/vs/envelope-vs-enveloped)

## Common misspellings (11)
`enevlope`, `ennvelope`, `envellope`, `enveloep`, `enveloppe`, `envelpoe`, `enveolpe`, `envleope`, `envvelope`, `evnelope`, `nevelope`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/envelope