Author George, essentially healthy (6)
I believe the answer is:
orwell
'author' is the definition.
(I've seen this before)
'george essentially healthy' is the wordplay.
'essentially' indicates the central letters.
'healthy' becomes 'well' ('well' can be similar in meaning to 'healthy').
The middle of 'george' is 'or'.
'or'+'well'='ORWELL'
(Other definitions for orwell that I've seen before include "banker" , "George ...... wrote 'Animal Farm' and '1984'" , "George --, British author" , "George --, novelist" , "Blair's pseudonym" .)