Talc I may spill - that's a disaster (8)
I believe the answer is:
calamity
'that's a disaster' is the definition.
(synonyms)
'talc i may spill' is the wordplay.
'spill' is an anagram indicator (letters spilled or knocked around).
'talc'+'i'+'may'='talcimay'
'talcimay' is an anagram of 'CALAMITY'.
(Other definitions for calamity that I've seen before include "15 [JANE] the frontierswoman" , "Event resulting in great loss and misfortune" , "Disaster, extreme misfortune" , "Disaster for wild west Jane" , "Blow" .)