Floating; not moored (6)
I believe the answer is:
adrift
This clue is a double definition.
'floating' is the first definition.
(similar in meaning)
'not moored' is the second definition.
(I've seen this in another clue)
(Other definitions for adrift that I've seen before include "Loose from moorings" , "Unanchored at sea" , "Afloat without steerage" , "not settled" , "Rudderless, astray" .)