Enormous snowdrop? (9)
I believe the answer is:
avalanche
'enormous snowdrop?' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for avalanche that I've seen before include "Sudden descent of massed snow etc" , "Landslide of snow" , "Mountainside fall" , "Large mass of sliding snow or stone" , "Deluge" .)