Greek character (5)
(Other definitions for ethos that I've seen before include "Characteristic culture of a culture or time" , "moral code" , "Distinctive group attitudes" , "Characteristic attitudes" , "Characteristic standards of those" .)
'greek character' is the definition.
(letter from the Greek alphabet)
This is all the clue.
(Other definitions for omega that I've seen before include "end of series" , "Final outcome" , "long letter" , "completes a series" , "16 letter" .)
'greek character' is the definition.
(letter from the Greek alphabet)
This is all the clue.
(Other definitions for alpha that I've seen before include "First in order of importance (for a Greek?)" , "Foremost" , "First (class)" , "First, best quality" , "Greek vowel" .)