- 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.
- push the envelope, to stretch established limits, as in technological advance or social innovation.
Origin of envelope
Examples from the Web for envelope
He started out with solo flights, but in this session over the desert outside Dubai he really pushes the envelope.Daredevil in a Jetpack Flies Alongside A Plane
Jack Holmes, The Daily Beast Video
December 12, 2014
The parental fold may be about to envelope you—and yet also drive you mad.How to Make It Through Thanksgiving Alive
November 26, 2014
On one occasion, Garrison said Williams had him hand one out-of-state doctor an envelope stuffed with $20,000 in cash.Patients Screwed in Spine Surgery ‘Scam’
The Center for Investigative Reporting
November 3, 2014
The envelope also contains a warning about the federal penalties for obstructing the mail.Grimes Campaign “Exploring Legal Options” Against McConnell
October 31, 2014
Prince William was seen clutching an envelope, when they left, most likely containing images of the scan.Royal Baby Due In April
October 20, 2014
He took the card from the florist's envelope and glanced at the name.
When she had gone he picked up an envelope and put a bill inside.
She drew it in pencil on an envelope on her way back in the street car.
"Because I want to do it myself," she said at last, and thrust the envelope into the flame.
Before I open this envelope I am going to tell you what I believe it contains.Her Father's Daughter
- 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 and History for envelope
1705, from French enveloppe (13c.), a back-formation from envelopper "to envelop" (see envelop).
- An enclosing structure or cover, such as a membrane or the outer coat of a virus.