Volcano back in Canterbury (4)
I believe the answer is:
etna
'volcano' is the definition.
(Mount Etna)
'back in canterbury' is the wordplay.
'back' says the letters should be written in reverse.
'in' says the answer is hidden in the clue.
'ante' is hidden within 'canterbury'.
'ante' written backwards gives 'ETNA'.
(Other definitions for etna that I've seen before include "It sometimes blows its top" , "A neat sort of volcano" , "hotly-tipped runner" , "Neat volcano overturned" , "Volcano; reverse of stake" .)