Shy before English class (5)
I believe the answer is:
caste
'class' is the definition.
(type of social class)
'shy before english' is the wordplay.
'shy' becomes 'cast' (both can mean to throw).
'before' is a charade indicator (letters next to each other).
'english' becomes 'E' (abbreviation).
'cast'+'e'='CASTE'
(Other definitions for caste that I've seen before include "Brahmans for instance" , "Hereditary Hindu social division" , "Hereditary social class among Hindus" , "Hereditary social class in Hindu society" , "Social position" .)