Remnant of ship in metal sheet (6)
I believe the answer is:
fossil
'remnant' is the definition.
(thesaurus)
'ship in metal sheet' is the wordplay.
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'in' means one lot of letters goes inside another.
'metal sheet' becomes 'foil' (foil is a kind of sheet. I am not sure about the 'metal' bit.).
'ss' placed inside 'foil' is 'FOSSIL'.
'of' is the link.
Can you help me to learn more?
(Other definitions for fossil that I've seen before include "Petrified 9" , "Remains of an ancient plant or animal" , "old boy?" , "Antiquated person" , "Remnant of life in a rock" .)