Nutty writer about a Manx cat (5)
I believe the answer is:
pecan
'nutty writer about a manx cat' is the definition.
I can't judge whether this definition defines the answer.
'writer about a manx cat' is the wordplay.
'writer' becomes 'pen' (something which writes).
'about' means one lot of letters goes inside another.
'a manx' means to remove the last letter (Manx cats have no tail).
'cat' with its final letter removed is 'ca'.
'pen' going around 'ca' is 'PECAN'.
Can you help me to learn more?
(Other definitions for pecan that I've seen before include "Nut with sweet oily kernel" , "Nut tree of the southern United States and Mexico" , "US nut tree" , "Pinkish-brown nut used in American pie" , "Nut of American hickory tree" .)