On tenancy agreement that's free (7)
I believe the answer is:
release
'free' is the definition.
(to release someone is to free them)
'on tenancy agreement' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'tenancy agreement' becomes 'lease' (I've seen this before).
're'+'lease'='RELEASE'
'that's' acts as a link.
(Other definitions for release that I've seen before include "Issue" , "put out" , "record" , "Liberate" , "Let go" .)