Jiffy bag

noun
1.
trademark a thickly padded but light envelope in which articles such as books are placed for protection in the post
Slang definitions & phrases for jiffy bag

jiffy bag

noun phrase
  1. A small canvas or leather bag for carrying toilet articles, etc, while traveling (WWII armed forces)
  2. (also Jiffy, a trademark) A heavy-walled paper bag used for mailing items, esp books (1970+)