Opening provided by random riots in Holland (7)
I believe the answer is:
nostril
'opening' is the definition.
(nostril is a kind of opening)
'random riots in holland' is the wordplay.
'random' is an anagram indicator.
'in' indicates putting letters inside.
'holland' becomes 'nl'.
'riots' with letters rearranged gives 'ostri'.
'ostri' placed within 'nl' is 'NOSTRIL'.
'provided by' acts as a link.
(Other definitions for nostril that I've seen before include "Breathing opening for a human" , "Nose hole" , "Nasal passageway" , "Part of nose" , "Nasal feature" .)