flyleaf

English Wikipedia has articles on:

flyleaf and flyleaf (book design)

Wikipedia Wikipedia

fly +‎ leaf

• IPA^(key): /ˈflaɪˌlif/

• Audio (US):

  (file)

flyleaf (plural flyleafs or flyleaves)

1. A blank leaf at the front or back of a book.
   • 2008 May 15, Alberto Manguel, “A 30,000-Volume Window on the World”, in New York Times‎^[1]:

     The scribbles on the margins, the occasional date on the flyleaf, the faded bus ticket marking a page for a reason today mysterious, all try to remind me of who I was then.

   1. Especially, the free portion of an endpaper.

      Holonym: endpaper

      Comeronym: pastedown

• “flyleaf”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.