Greek character gone astray in Homer? (6)
I believe the answer is:
pigeon
'homer?' is the definition.
(homer is a kind of pigeon)
'greek character gone astray in' is the wordplay.
'greek character' becomes 'pi' (letter from the Greek alphabet**).
'astray' indicates anagramming the letters.
'in' means one lot of letters goes inside another.
'gone' is an anagram of 'geon'.
'pi' going inside 'geon' is 'PIGEON'.
(Other definitions for pigeon that I've seen before include "Go pine for the bird" , "Short-legged bird" , "Bird of towns and woods" , "Bird of the dove family" , "gull" .)