Spontaneous occurrence before the public holiday (8)
I believe the answer is:
outbreak
'spontaneous occurrence' is the definition.
'outbreak' can be an answer for 'occurrence' (outbreak is a kind of occurrence). I am not certain of the 'spontaneous' bit.
'the public holiday' is the wordplay.
'the public' becomes 'out' (out can mean released to the public).
'holiday' becomes 'break' (break can mean a holiday or time off).
'out'+'break'='OUTBREAK'
'before' is the link.
Can you help me to learn more?
(Other definitions for outbreak that I've seen before include "Sudden onset (of war, disease, etc)" , "Sudden occurrence (of war, disease, etc.)" , "disturbance" , "Sudden spontaneous occurrence" , "Sudden start" .)