Calm stay disrupted round clubs is disaster (9)
I believe the answer is:
cataclysm
'disaster' is the definition.
(synonyms)
'calm stay disrupted round clubs' is the wordplay.
'disrupted' is an anagram indicator.
'round' is an insertion indicator.
'clubs' becomes 'c' (abbreviation used in card games such as bridge).
'calm'+'stay'='calmstay'
'calmstay' with letters rearranged gives 'catalysm'.
'catalysm' going around 'c' is 'CATACLYSM'.
'is' acts as a link.
(Other definitions for cataclysm that I've seen before include "Deluge: upheaval" , "Sudden violent change in the earth's surface" , "A clam cyst could be a disaster" , "Event resulting in great loss and misfortune" , "Calamity" .)