Greying, grizzled and nursing a light head with extreme care (8)
I believe the answer is:
gingerly
'greying grizzled and nursing a light' is the definition.
I can't tell whether this defines the answer.
'head with extreme care' is the wordplay.
'head with' becomes 'ginger' (I can't justify this - if you can you should give a lot more credence to this answer).
'extreme' suggests removing the centre.
'care' becomes 'livery' (livery is a kind of care).
'livery' with its middle removed is 'ly'.
'ginger'+'ly'='GINGERLY'
Can you help me to learn more?
(Other definitions for gingerly that I've seen before include "Cautiously (as if in pain?)" , "In a careful manner" , "With extreme care and delicacy" , "With soft steps" , "Showing caution" .)