Little South American hurt by flash mob (8)
I believe the answer is:
marmoset
'little south american' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'hurt by flash mob' is the wordplay.
'hurt' becomes 'mar' (both can mean to harm).
'by' is a charade indicator (letters next to each other).
'flash' becomes 'mo' (both mean a very short period of time).
'mob' becomes 'set' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mar'+'mo'+'set'='MARMOSET'
Can you help me to learn more?
(Other definitions for marmoset that I've seen before include "Small South American monkey" , "Arms me to (anag) - animal" , "Small New World monkey" , "Little monkey" , "Turn morse mat over for the monkey" .)