Volcano with molten rock rising, ejecting tons round constant hot flood (9)
I believe the answer is:
avalanche
'flood' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for avalanche that I've seen before include "Mountainside fall" , "Great snowfall" , "Slide of large amounts of snow or stone" , "Rock-fall" , "great fall" .)