Agreement at home -- something taken out overnight? (9)
I believe the answer is:
indenture
'agreement' is the definition.
(I know that indenture is a type of written agreement)
'home something taken out overnight?' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'something taken out overnight?' becomes 'denture' (dentures are taken out overnight).
'in'+'denture'='INDENTURE'
'at' is the link.
(Other definitions for indenture that I've seen before include "Bind to service" , "served by a novice?" , "Document" , "Agreement binding apprentice to a master" , "Sealed agreement" .)