Casual shoe or idler (6)
I believe the answer is:
loafer
I believe this clue is a double definition.
'casual shoe' is the first definition.
(I've seen this before)
'idler' is the second definition.
(I know that idler can be written as loafer)
(Other definitions for loafer that I've seen before include "idle type" , "Fanciful baker" , "Style of shoe" , "one going on foot?" , "maybe put foot in it" .)