Pure Hindu class around the centre (6)
I believe the answer is:
chaste
'pure' is the definition.
(chaste means abstaining from sex)
'hindu class around the centre' is the wordplay.
'hindu class' becomes 'caste' (I've seen this in another clue).
'around' indicates putting letters inside.
'centre' says to take the centre.
The central letter of 'the' is 'h'.
'caste' placed around 'h' is 'CHASTE'.
(Other definitions for chaste that I've seen before include "virgin" , "Like Diana" , "Sexually virtuous" , "Pure and virginal" , "He-cats could be virtuous, strangely" .)