Long hair round neck unshaven, you'd say (4)
I believe the answer is:
ruff
'long hair round' is the definition.
'ruff' can be an answer for 'round' (thesaurus). I'm unsure of the 'long hair' bit.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for ruff that I've seen before include "Male sandpiper" , "Starched, frilled collar" , "Trump; male shore bird" , "Pleated frill worn round the neck" , "Type of collar" .)