billfold

名词 billfold:

1. a pocket-size case for holding papers and paper money
   同义词：wallet, notecase, pocketbook

bill.fold

n.（名词）
A folding pocket-sized case for carrying paper money, small personal documents, and sometimes change.
钱夹：一种用来放钞票、私人小文件和一些零钱的可折叠的便于携带的夹子