Purposeful action saves time at home (10)
I believe the answer is:
determined
'purposeful' is the definition.
(synonyms)
'action saves time at home' is the wordplay.
'action' becomes 'deed' (deed is a kind of action).
'saves' is an insertion indicator.
'time' becomes 'term' (term can mean a period of time).
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'term'+'in'='termin'
'deed' placed around 'termin' is 'DETERMINED'.
(Other definitions for determined that I've seen before include "set" , "Found out" , "Decided - resolute" , "Firmly decided" , "firm" .)