Son certain about the present being kept in the house? (9)
I believe the answer is:
snowbound
'kept in the house?' is the definition.
(kept in the house by snow)
'son certain about the present' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'certain' becomes 'bound' (as in the phrase 'it's bound to be').
'about' means one lot of letters go next to another.
'the present' becomes 'now' (both can mean the current period).
'bound' after 'now' is 'nowbound'.
's'+'nowbound'='SNOWBOUND'
'being' is the link.
(Other definitions for snowbound that I've seen before include "Arctic explorer could be so" , "cut off by fall" , "Hampered by wintry conditions" , "restricted by weather" , "immobilised by weather" .)