An everyday English word carries a Latin cushion inside it.
Pillow reaches back through Middle English pilwe and Old English pyle to Latin pulvinus. A familiar everyday object can carry an old borrowing whose spelling has changed enough to conceal the connection.
This selects the forms given in the dictionary; the German relative is not a required intermediate stage.
Sources
- Merriam-Webster: pillow
Word History supplies the selected route and marks pfuliwi as a related form.
- Merriam-Webster: pulvinus
Word History glosses the Latin source as cushion; the botanical use is not part of the puzzle.