Most free facilities bedsit’s occasionally lacking (7)
I believe the answer is:
loosest
'most free' is the definition.
(loose can mean free or relaxed)
'facilities bedsit's occasionally lacking' is the wordplay.
'facilities' becomes 'loos' (loo is a kind of facility).
'occasionally lacking' means one should take alternating letters (letters removed at regular intervals or occasions).
The alternate letters of 'bedsit' are 'est'.
'loos'+'est'='LOOSEST'
(Other definitions for loosest that I've seen before include "most unstable" , "most relaxed" .)