Volcano back in Canterbury (4)
I believe the answer is:
etna
'volcano' is the definition.
(Mount Etna)
'back in canterbury' is the wordplay.
'back' is a reversal indicator.
'in' indicates a hidden word.
'ante' is hidden in the letters of '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" .)