Plans to hold religious classes in French cathedral (8)
I believe the answer is:
chartres
'french cathedral' is the definition.
'chartres' can be an answer for 'cathedral' (French cathedral). I'm not certain of the 'french' bit.
'plans to hold religious classes' is the wordplay.
'plans' becomes 'charts' (charting is a kind of planning).
'to hold' indicates putting letters inside.
'religious classes' becomes 're' (I can't justify this - if you can you should give a lot more credence to this answer).
'charts' enclosing 're' is 'CHARTRES'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for chartres that I've seen before include "French town noted for its Gothic cathedral" , "City southwest of Paris - arch rest (anag)" , "French town with famous cathedral" , "Beauce town, Gothic cathedral" , "Famous French cathedral city" .)