Casual, free and easy (8)
I believe the answer is:
informal
I believe this clue is a double definition.
'casual' is the first definition.
(similar in meaning)
'free and easy' is the second definition.
(I've seen this before)
(Other definitions for informal that I've seen before include "Casual, not official" , "Cosy -- loose" , "Casual, free and easy" , "Unofficial, relaxed" , "Casual or unofficial" .)