Well-prepared speech about a new King Charles? (7)
I believe the answer is:
spaniel
'king charles?' is the definition.
The definition suggests a singular noun which matches the answer.
'well-prepared speech about a new' is the wordplay.
'well prepared speech' becomes 'spiel' (I can't explain this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'a'+'n'='an'
'spiel' enclosing 'an' is 'SPANIEL'.
Can you help me to learn more?
(Other definitions for spaniel that I've seen before include "[HOUND]" , "See 13" , "Droopy-ear dog" , "Type of dog" , "Animal" .)