Ladies and gentlemen relaxed briefly (4)
I believe the answer is:
loos
'ladies and gentlemen' is the definition.
'relaxed briefly' is the wordplay.
'relaxed' becomes 'loose' (loose can mean flexible or unrestricted).
'briefly' means to remove the last letter.
'loose' with its final letter taken off is 'LOOS'.
(Other definitions for loos that I've seen before include "Austrian architect" , "Conveniences" .)