Refusal to speak of riotous license (7)
I believe the answer is:
silence
'refusal to speak' is the definition.
I can't judge whether this defines the answer.
'riotous license' is the wordplay.
'riotous' is an anagram indicator.
'license' with letters rearranged gives 'SILENCE'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for silence that I've seen before include "What's left of burnt coal" , "Soundlessness" , "It is said to be golden" , "Gag" , "No talking" .)