Playing Cluedo - Mr Green's conclusion: it might be in the kitchen with a knife (5,4)
I believe the answer is:
lemon curd
'it might be in the kitchen with a knife' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'playing cluedo mr green's conclusion' is the wordplay.
'playing' indicates anagramming the letters.
'conclusion' says to take the final letters.
The last letter of 'green' is 'n'.
'cluedo'+'mr'+'n'='cluedomrn'
'cluedomrn' anagrammed gives 'LEMON CURD'.
Can you help me to learn more?
(Other definitions for lemon curd that I've seen before include "Yellow stuff" , "Thick yellow conserve" , "Thick, sweet spread" , "Yellow goo" .)