/'envələʊp, also'ɒn-; `ɛnvə,lop, `ɑnvə,lop/
n wrapper or covering, esp one made of paper for a letter 封套; 封皮; （尤指）信封
*writing paper and envelopes 信纸和信封
* an airmail envelope 航空信封.
1700-1800; Language: French;Origin:
enveloppe, from Old French
a thin paper cover in which you put and send a letter envelopes and stamps She tore open the envelope and frantically read the letter. He got a job stuffing envelopes (=filling them with letters) at the campaign headquarters.
a layer of something that surrounds something elseenvelope of an envelope of gases around the planetpush the envelopeAmE
to try to go beyond the normal limits of something a musician who pushes the envelope of improvisation
1. The envelope tears easily. 这种信封容易扯破。
2. The best way to open an envelope is to slit it at the top. 拆信的最好方法是在顶部拆开。
3. No, it would be the worn, fading envelope she kept for so long. 都不是，要抢出来的该是那个已经保存很久并已破旧、发黄了的信封。
4. A girl came in and put an envelope on his desk. It contained $ 50 . 一个姑娘进来，把一个信封放在桌上，里面有五十英镑。
5. A girl came in and put an envelope on his desk. 一个姑娘走了进来，把一个信封放在了他桌上。
6. She wrote a note on the envelope and left it on his book: "Husband, I have gone next door to help Mrs. Norton with her sick children." 她在信封上写了一行留言，放在他的书上：“老公，我去隔壁帮诺顿太太照顾她的几个生病的孩子了。”
7. One evening her husband came home with a triumphant air, holding in his hand a large envelope. 一天晚上，她丈夫下班回来带着一副得意的神气，手里拿着一个大信封。