Stupidly deal in LSD: disaster (9)
I believe the answer is:
landslide
'disaster' is the definition.
The definition and answer can be both related to natural events as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'stupidly deal in lsd' is the wordplay.
'stupidly' is an anagram indicator (a stupid ordering of the letters).
'deal'+'in'+'lsd'='dealinlsd'
'dealinlsd' is an anagram of 'LANDSLIDE'.
Can you help me to learn more?
(Other definitions for landslide that I've seen before include "Huge majority at election" , "big victory" , "Runaway" , "Overwhelming election win" , "easy victory" .)