Silly chatter is what you expect from melodramatic people (9)
I believe the answer is:
theatrics
'you expect from melodramatic people' is the definition.
I can't judge whether this defines the answer.
'silly chatter is' is the wordplay.
'silly' indicates anagramming the letters.
'chatter'+'is'='chatteris'
'chatteris' with letters rearranged gives 'THEATRICS'.
'what' is the link.
Can you help me to learn more?
(Other definitions for theatrics that I've seen before include "Histrionics" , "dramatic outburst" .)