To a Cockney, the hat-tricks sound like emotional displays (9)
I believe the answer is:
theatrics
'sound like emotional displays' is the definition.
The definition suggests a singular noun which matches the answer.
'to a cockney the hat-tricks' is the wordplay.
I cannot quite understand how this works, but
'a' is within the answer.
an anagram of 'the' is 'het' which is located in the remaining letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for theatrics that I've seen before include "dramatic outburst" , "Histrionics" .)