Stake raised in volcano (4)
I believe the answer is:
etna
'volcano' is the definition.
(Mount Etna)
'stake raised' is the wordplay.
'stake' becomes 'ante' (stake in poker).
'raised' is a reversal indicator (going up in a down clue).
'ante' in reverse letter order is 'ETNA'.
'in' is the link.
(Other definitions for etna that I've seen before include "Impressive mount" , "From a dangerous height" , "Dangerous peak" , "Threatening mountain" , "Sicilian landmark" .)