Mother, child and secretive lodger? (5)
I believe the answer is:
mason
'secretive lodger?' is the definition.
'mother child' is the wordplay.
'mother' becomes 'ma' (ma can mean mother).
'child' becomes 'son' (son is a kind of child).
'ma'+'son'='MASON'
'and' is the link.
(Other definitions for mason that I've seen before include "Stone-carver" , "Craftsman - English film actor, d. 1984" , "Actor James" , "Secret society member" , "US comedian" .)