briefcase
Word family nounbriefingbriefnessbriefcaseadjectivebrieflessbriefadverbbriefly
Daily life
brief·case /ˈbriːfkeɪs/ ●●○ noun [countableC] 
BDa flat case used especially by business people for carrying papers or documents 公文包，公事包 →4 See picture on 见图 Page A8 In the office 办公室里 →5 see picture at 见图 case, officeExamples from the Corpus
briefcase• It had become compact enough to sit on a desk or slip into a briefcase.• He has also ditched his briefcase for a backpack to carry his dress shoes.• Simon Jay had his briefcase and cassette radio stolen from his car this morning.• Ivor thought she might have gone through his briefcase and found a letter from me.• I rammed my books and my binders into my briefcase.• He puts his green plastic briefcase on the desk.• Converse carried the briefcase through the hurrying evening crowds on Le Loi, walking as casually as he could.• Put a copy in your locked desk drawer and another in the secret compartment of your briefcase.
From Longman Business Dictionary
briefcasebrief·case /ˈbriːfkeɪs/ noun [countableC]OFFICE
a case used for carrying papers or documents