Piece of germanium (3)
I believe the answer is:
man
'piece' is the definition.
('man' can be a synonym of 'piece')
'of germanium' is the wordplay.
'of' indicates a hidden word.
'MAN' is hidden within 'germanium'.
(Other definitions for man that I've seen before include "Attendant" , "just one" , "See 24" , "Vassal; chess piece" , "Staff the island" .)