Loose robes, not at all tight (5)
I believe the answer is:
sober
'not at all tight' is the definition.
'loose robes' is the wordplay.
'loose' indicates an anagram (letters are loosened from their original positions).
'robes' with letters rearranged gives 'SOBER'.
(Other definitions for sober that I've seen before include "Far from drunk" , "Earnest" , "Dry - dull" , "Serious, dull" , "Dignified -- lacking colour" .)