Prevented from being a drifter (6)
I believe the answer is:
moored
'prevented' is the definition.
Although both the answer and definition are past participle verbs, I cannot understand how one could define the other.
'being a drifter' is the wordplay.
'being' becomes 'moor' (Moor is an example).
'a drifter' becomes 'ed' (I can't justify this - if you can you should believe this answer much more).
'moor'+'ed'='MOORED'
'from' is the link.
Can you help me to learn more?
(Other definitions for moored that I've seen before include "Tied up to berth like ship or boat" , "Berthed, tied up" , "Secured by rope or cable" , "Of boat, tied up or secured" , "Made fast" .)