envelope

1. N-COUNT An envelope is the rectangular paper cover in which you send a letter to someone through the mail. 信封

2. PHRASE If someone pushes the envelope, they do something to a greater degree or in a more extreme way than it has ever been done before. 挑戰(zhàn)極限; 突破常規(guī)

There's a valuable place for fashion and design that pushes the envelope a bit. 突破點(diǎn)兒常規(guī)的時(shí)尚和設(shè)計(jì)有其寶貴地位。