Peg possibly owed a pound (5)
I believe the answer is:
dowel
'peg' is the definition.
(thesaurus)
'possibly owed a pound' is the wordplay.
'possibly' indicates anagramming the letters.
'a pound' becomes 'l'.
'owed' anagrammed gives 'dowe'.
'dowe'+'l'='DOWEL'
(Other definitions for dowel that I've seen before include "Pin that holds two pieces of wood together" , "Lowed (anag.)" , "Headless peg used for joining components" , "Pole" , "Linking peg" .)