envelope /ˈɛnvəˌloʊp/ /ˈɑːnvəˌloʊp/ noun plural envelopes
/ˈɛnvəˌloʊp/ /ˈɑːnvəˌloʊp/
noun
plural envelopes
Learner's definition of ENVELOPE
[count]
: an enclosing cover for a letter, card, etc.信封 — see picture at mail
push the envelope
: to go beyond the usual or normal limits by doing something new, dangerous, etc.突破极限;挑战极限