汉语翻译：
n. 信封, 封套, 封袋
【医】 膜, 包袋英语解释：
名词 envelope:
a flat rectangular paper container for papers
any wrapper or covering
a curve that is tangent to each of a family of curves
a natural covering (as by a fluid)
the maximum operating capability of a system
the bag containing the gas in a balloon同义词：gasbag
例句：
Does the name on the envelope correspond with the name on the letter inside?信封上的名字与里面信上的名字是否相同?
There are several enclosures in the envelope.信封内装有几份附件。
He steamed the stamp off the envelope.他用蒸汽把信封上的邮票揭下来。
I use a prepaid envelope.我用了一个邮资已付的信封。
A paper or thin cardboard envelope for a phonograph record.唱片套子留声机唱片的纸套或薄纸板封套
He glued a stamp onto the envelope.他把邮票贴在信封上。
The envelope was firmly sealed.这个信封封得很严实。
He addressed the envelope before mailing the letter.寄信前，他在信封上写上地址。
详细解释：
en.ve.lope
n.（名词）
A flat, folded paper container, especially for a letter.
信封：扁平，装折叠纸的容器，尤其用来装信
Something that envelops; a wrapping.
包裹物；封皮
Biology An enclosing structure or cover, such as a membrane or the outer coat of a virus.
【生物学】 膜，包袋：包裹性的结构或 * ，如膜或病毒的外壳
The bag containing the gas in a balloon or an airship.
气囊：气球或飞艇上容纳气体的袋装物
The set of limitations within which a technological system, especially an aircraft, can perform safely and effectively.
极限数据：技术系统，尤其是飞机，能够安全有效运转的一系列界限
The coma of a comet.
彗星的彗发
Mathematics A curve or surface that is tangent to every one of a family of curves or surfaces.
【数学】 包络线，包络面：一条曲线或一个曲面，与一组曲线或曲面中的每一曲线或曲面保持正切
<习惯用语>push the envelope
To increase the operating capabilities of a technological system.
增强技术系统的运转能力
来源：
French enveloppe
法语 enveloppe
from envelopper [to envelop]
源自 envelopper [包住]
from Old French envoloper * see envelop
源自 古法语 envoloper *参见 envelop
