envelope

noun en·ve·lope \ ˈen-və-ˌlōp , ˈän- \
Updated on: 16 Nov 2017

Definition of envelope

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?

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.


Recent Examples of envelope from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'envelope.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of envelope

circa 1714

Other Paper Terms



ENVELOPE Defined for English Language Learners

envelope

noun

Definition of envelope for English Language Learners

  • : an enclosing cover for a letter, card, etc.


ENVELOPE Defined for Kids

envelope

noun en·ve·lope \ ˈen-və-ˌlōp , ˈän- \

Definition of envelope for Students

: a flat usually paper container (as for a letter)

Medical Dictionary

envelope

noun en·ve·lope \ ˈen-və-ˌlōp , ˈän- \

medical Definition of envelope

: 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 AmericanOctober 1988


Seen and Heard

What made you want to look up envelope? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

sticky or viscid

Get Word of the Day daily email!

Test Your Vocabulary

Find the Cousins

  • a-large-tree-with-many-branches
  • Which pair shares a common word ancestor?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!