Ruin chinchilla, perhaps when adjusting her top (11)
I believe the answer is:
catastrophe
'ruin chinchilla' is the definition.
The answer and definition can be both related to natural events as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'perhaps when adjusting her top' is the wordplay.
'perhaps' becomes 'cat' (I can't justify this - if you can you should believe this answer much more).
'when' becomes 'as' (eg 'when I walked' means 'as I walked').
'adjusting' indicates anagramming the letters.
'her'+'top'='hertop'
'hertop' with letters rearranged gives 'trophe'.
'cat'+'as'+'trophe'='CATASTROPHE'
Can you help me to learn more?
(Other definitions for catastrophe that I've seen before include "Calamity" , "Great disaster" , "Sudden disaster" , "Event causing much damage" , "final event" .)