European insect going up volcano (4)
I believe the answer is:
etna
'volcano' is the definition.
(Etna is an example)
'european insect going up' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'insect' becomes 'ant' (ant is a kind of insect).
'going up' is a reversal indicator.
'ant' in reverse letter order is 'tna'.
'e'+'tna'='ETNA'
(Other definitions for etna that I've seen before include "Neat (anag)" , "Threatening mountain" , "From a dangerous height" , "Dangerous peak" , "it may produce steam and ash" .)