envelope
envelope Lexical Profile
envelope Game Scores & Validity
• noun
A flat paper container with a sealable flap, primarily used to enclose a letter, card, or document for mailing or delivery.
"She carefully slipped the handwritten wedding invitation into a beautifully lined envelope."
The known limits of safe performance or capabilities for a system, aircraft, or concept, often used in the idiom 'pushing the envelope'.
"The test pilots were celebrated for consistently pushing the flight envelope of experimental aircraft to see what the machines could truly handle."
An enclosing structure or cover, such as the outer fabric of a hot-air balloon or the protective outer membrane of a virus.
"The hot air balloon's brightly colored envelope slowly inflated as the burner roared to life."
Word Nuance & Usage
Carefully distinguish the noun 'envelope' (a container or boundary) from the verb 'envelop' (to wrap or surround completely), which lacks the final 'e' and is stressed on the second syllable.
Word Origin & Etymology
Early 18th century: from French enveloppe, from the verb envelopper 'to wrap up', derived from Old French envoluper.
Usage Trend
Historical frequency of usage in published text.