Some inhabiting other block (5)
I believe the answer is:
ingot
'block' is the definition.
(ingot is a kind of block)
'some inhabiting other' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'INGOT' is hidden in the letters of 'inhabiting other'.
(Other definitions for ingot that I've seen before include "Mass of metal, especially gold or silver" , "expensive block" , "Mass of cast metal" , "Piece of precious metal" , "Form of gold or silver" .)