Core (of atom) (7)
I believe the answer is:
nucleus
(Other definitions for nucleus that I've seen before include "Central part of thing - ask us, uncle" , "part of comet's head" , "Central mass of a cell" , "Tiny factor" , "Core, centre" .)
I believe the answer is:
nucleus
(Other definitions for nucleus that I've seen before include "Central part of thing - ask us, uncle" , "part of comet's head" , "Central mass of a cell" , "Tiny factor" , "Core, centre" .)