Social class arranged seat with Charlie (5)
I believe the answer is:
caste
'social class' is the definition.
(caste is a kind of social class)
'arranged seat with charlie' is the wordplay.
'arranged' indicates anagramming the letters.
'with' says to put letters next to each other.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.**).
'seat' with letters rearranged gives 'aste'.
'aste' after 'c' is 'CASTE'.
(Other definitions for caste that I've seen before include "Social position" , "Social class or rank" , "Hereditary social class in Hindu society" , "Religious or social class" , "Social division in Hinduism" .)