Still at home? Finally leave after breakfast (5)
I believe the answer is:
inert
'still' is the definition.
(thesaurus)
'home? finally leave after breakfast' is the wordplay.
'home?' becomes 'in' ('he's home' can mean 'he's in').
'finally' suggests the final letters.
The final letters of 'leave after breakfast' are 'ert'.
'in'+'ert'='INERT'
'at' acts as a link.
(Other definitions for inert that I've seen before include "(Chem.) not reactive" , "Nothing doing" , "like nitrogen" , "Not chemically active" , "Sluggish, still" .)