Pathetic riot of three people (4)
I believe the answer is:
trio
'of three people' is the definition.
The definition suggests a singular noun which matches the answer.
'pathetic riot' is the wordplay.
'pathetic' indicates an anagram (a pathetically bad ordering of the letters).
'riot' with letters rearranged gives 'TRIO'.
Can you help me to learn more?
(Other definitions for trio that I've seen before include "Group of three (musicians)" , "Chamber group" , "wise men?" , "Work for three" , "Three together" .)