The piece of paper containing these letters (5)
I believe the answer is:
sheet
'the piece of paper' is the definition.
(synonyms)
'these letters' is the wordplay.
'letters' indicates anagramming the letters.
'these' is an anagram of 'SHEET'.
'containing' acts as a link.
(Other definitions for sheet that I've seen before include "Piece of paper, linen, or water" , "Piece of paper; nautical rope" , "Large piece of fabric" , "Piece of paper or bedding" , "Piece of paper or bedlinen" .)