Certainly at home there will be something to do (6)
I believe the answer is:
indeed
'certainly' is the definition.
(both can be used to answer in the affirmative)
'home there will be something to do' is the wordplay.
I cannot quite understand how this works, but
'home' could be 'in' ('he's home' can mean 'he's in') and 'in' is present in the answer.
'something to do' could be 'deed' (I've seen this in another clue) and 'deed' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'at' acts as a link.
Can you help me to learn more?
(Other definitions for indeed that I've seen before include "Unquestionably" , "Truthfully, really" , "Certainty" , "Expression of interest, incredulity or contempt" , "In reality" .)