Sick man digesting lines about native of ancient region (8)
I believe the answer is:
illyrian
'native of ancient region' is the definition.
(I know that Illyrian is the class of people from Illyria)
'sick man digesting lines about' is the wordplay.
'sick' becomes 'ill' (similar in meaning).
'man' becomes 'Ian' (man's name).
'digesting' means one lot of letters goes inside another (inserted letters are eaten or ingested).
'lines about' becomes 'yr' (I can't justify this - if you can you should believe this answer much more).
'ill'+'ian'='illian'
'illian' placed around 'yr' is 'ILLYRIAN'.
(Other definitions for illyrian that I've seen before include "language from Albania" , "old foreign language" .)