Emperor on plane eating old nuts (8)
I believe the answer is:
napoleon
'emperor' is the definition.
(I know this)
'on plane eating old nuts' is the wordplay.
I cannot quite understand how this works, but
'on' is found in the answer.
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is found within the answer.
an anagram of 'plane' is 'naple' which is within the left over letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for napoleon that I've seen before include "In France, former sovereign" , "Corporal and emperor" , "Emperor - brandy" , "leader in France, once" , "Open loan to the French general. strangely" .)