Worthless people finally put in cellar (8)
I believe the answer is:
basement
'cellar' is the definition.
(both can mean the space underneath a house)
'worthless people finally put' is the wordplay.
'worthless' becomes 'base' (I've seen this before).
'people' becomes 'men' (men are people).
'finally' suggests the final letters.
The final letter of 'put' is 't'.
'base'+'men'+'t'='BASEMENT'
'in' is the link.
(Other definitions for basement that I've seen before include "Man beset in bottom of house" , "Part of house below ground" , "Lowest floor of a building" , "low point" , "room's full!" .)