The definition of an envelope is a container made of folded paper or cardboard.(noun)
An example of an envelope is what you would seal a letter in before mailing it to someone.
See envelope in Webster's New World College Dictionary
Origin: Fr & OFr enveloppe < OFr envoluper: see envelop
See envelope in American Heritage Dictionary 4
Origin: French enveloppe
Origin: , from envelopper, to envelop
Origin: , from Old French envoloper; see envelop. Usage Note: The word envelope was borrowed into English from French during the early 18th century, and the first syllable acquired the pronunciation (ŏn) as an approximation to the nasalized French pronunciation. Gradually the word has become anglicized further and is now most commonly pronounced (ĕnˈvə-lōpˌ). The earlier pronunciation is still considered acceptable, however. A recent survey reveals that the (ŏnˈ-) pronunciation for the word envelope is used by 30 percent of the Usage Panel and is recognized as an acceptable variant by about 20 percent of those Panelists who normally use the (ĕnˈ-) pronunciation. Other similar words borrowed from French in the modern period include envoy (17th century), encore, ennui, ensemble, entree (18th century), entourage, and entrepreneur (19th century). Most retain their pseudo-French pronunciations, with the exception of envoy, which, like envelope, is mainly pronounced with (ĕn) now.
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