Put off best Grange once opened (8)
I believe the answer is:
estrange
'put off' is the definition.
(I've seen this in another clue)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for estrange that I've seen before include "may break up" , "Drive away" , "Anger set (anag.)" , "Alien" , "Reagents (anag.)" .)