School hurt endlessly by quarrel (6)
I believe the answer is:
harrow
'school' is the definition.
(famous UK public school)
'hurt endlessly by quarrel' is the wordplay.
'hurt' becomes 'harm' (synonyms).
'endlessly' means to remove the last letter.
'by quarrel' becomes 'row' (synonyms. I am not sure about the 'by' bit.).
'harm' with its final letter removed is 'har'.
'har'+'row'='HARROW'
Can you help me to learn more?
(Other definitions for harrow that I've seen before include "Soil-breaking implement" , "Soil cultivator - English public school" , "Equipment provided for ground-breaking" , "Cultivator that breaks up the soil" , "Break up (ground) - distress (feelings)" .)