One needing rest in Greek character's location (6)
I believe the answer is:
milieu
'location' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'one needing rest in greek character's' is the wordplay.
'one' becomes 'i' (Roman numeral).
'needing' is a charade indicator (letters next to each other).
'rest' becomes 'lie' (lying is a kind of resting**).
'in' means one lot of letters goes inside another.
'greek character' becomes 'mu' (letter from the Greek alphabet).
'i'+'lie'='ilie'
'ilie' inserted within 'mu' is 'MILIEU'.
Can you help me to learn more?
(Other definitions for milieu that I've seen before include "Social environment or set of surroundings" , "'Surroundings, setting (6)'" , "Surroundings - location" , "Environmental condition, surrounding" , "(Social) setting" .)