ENVELOPE
envelope
(noun) any wrapper or covering
envelope
(noun) a flat (usually rectangular) container for a letter, thin package, etc.
envelope, gasbag
(noun) the bag containing the gas in a balloon
envelope
(noun) the maximum operating capability of a system (especially an aircraft); “test pilots try to push the envelope”
envelope
(noun) a natural covering (as by a fluid); “the spacecraft detected an envelope of gas around the comet”
envelope
(noun) a curve that is tangent to each of a family of curves
Source: WordNet® 3.1
Etymology 1
Noun
envelope (plural envelopes)
A paper or cardboard wrapper used to enclose small, flat items, especially letters, for mailing.
Something that envelops; a wrapping.
A bag containing the lifting gas of a balloon or airship; fabric that encloses the gas-bags of an airship.
(geometry) A mathematical curve, surface, or higher-dimensional object that is the tangent to a given family of lines, curves, surfaces, or higher-dimensional objects.
(electronics) A curve that bounds another curve or set of curves, as the modulation envelope of an amplitude-modulated carrier wave in electronics.
(music) The shape of a sound, which may be controlled by a synthesizer or sampler.
(computing) The information used for routing a message that is transmitted with the message but not part of its contents.
(biology) An enclosing structure or cover, such as a membrane; a space between two membranes
(engineering) The set of limitations within which a technological system can perform safely and effectively.
(astronomy) The nebulous covering of the head or nucleus of a comet; a coma.
An earthwork in the form of a single parapet or a small rampart, sometimes raised in the ditch and sometimes beyond it.
Synonyms
• (something that envelops): wrapper
• (bag containing the lifting gas): gasbag
Etymology 2
Verb
envelope (third-person singular simple present envelopes, present participle enveloping, simple past and past participle enveloped)
Archaic form of envelop.
Source: Wiktionary
En"vel*ope, En*vel"op, n. Etym: [F. enveloppe.]
1. That which envelops, wraps up, encases, or surrounds; a wrapper;
an inclosing cover; esp., the cover or wrapper of a document, as of a
letter.
2. (Astron.)
Definition: The nebulous covering of the head or nucleus of a comet; --
called also coma.
3. (Fort.)
Definition: A work of earth, in the form of a single parapet or of a small
rampart. It is sometimes raised in the ditch and sometimes beyond it.
Wilhelm.
4. (Geom.)
Definition: A curve or surface which is tangent to each member of a system
of curves or surfaces, the form and position of the members of the
system being allowed to vary according to some continuous law. Thus,
any curve is the envelope of its tangents. push the envelope. It is
used to refer to the maximum performance available at the current
state of the technology, and therefore refers to a class of machines
in general, not a specific machine. push the envelope Increase the
capability of some type of machine or system; -- usu. by
technological development.
Source: Webster’s Unabridged Dictionary 1913 Edition