Communicate to pupil about one area without prejudice (9)
I believe the answer is:
impartial
'without prejudice' is the definition.
I can't judge whether this definition defines the answer.
'communicate to pupil about one area' is the wordplay.
'communicate' becomes 'impart' (impart can mean to communicate or pass on).
'to pupil' becomes 'L' (as in L-plates for a learner driver).
'about' is a charade indicator (letters next to each other).
'one' becomes 'i' (Roman numeral).
'area' becomes 'a' (maths abbreviation).
'i'+'a'='ia'
'l' after 'ia' is 'ial'.
'impart'+'ial'='IMPARTIAL'
Can you help me to learn more?
(Other definitions for impartial that I've seen before include "Treating all rivals equally" , "Fair, unprejudiced" , "Showing lack of favouritism" , "Objective" , "Unbiased" .)