Piece of jewellery author and poet shortened (7)
I believe the answer is:
pendant
'piece of jewellery' is the definition.
(pendant is a type of jewellery item)
'author and poet shortened' is the wordplay.
'author' becomes 'pen' (to pen something is to author it).
'and' says to put letters next to each other.
'poet' becomes 'Dante' (13th- and 14th-century Italian poet).
'shortened' means to remove the last letter.
'dante' with its last letter taken away is 'dant'.
'pen'+'dant'='PENDANT'
(Other definitions for pendant that I've seen before include "Ornament hanging from a piece of jewellery" , "Ornament hanging from necklace" , "Panted after learned one" , "earring, say" , "Hanging light" .)