About a thousand in Italy involved in disaster (8)
I believe the answer is:
calamity
'disaster' is the definition.
(I've seen this before)
'about a thousand in italy involved' is the wordplay.
'about' becomes 'ca' (abbreviation for 'circa'**).
'a thousand' becomes 'm' ('M' can be a synonym of 'thousand').
'in' indicates putting letters inside.
'involved' indicates an anagram (involved can mean confusing or complex).
'italy' with letters rearranged gives 'laity'.
'm' going into 'laity' is 'lamity'.
'ca'+'lamity'='CALAMITY'
'in' acts as a link.
(Other definitions for calamity that I've seen before include "Disaster, extreme misfortune" , "Blow" , "Disaster, sudden great misfortune" , "Musical set in Deadwood" , "Catastrophe" .)