Despicable person pursuing dagger as a fashion item (8,4)
I believe the answer is:
stiletto heel
'a fashion item' is the definition.
'stiletto heel' can be an answer for 'item' (I have seen 'Pointed item' mean 'stiletto heel' so perhaps 'item' could also mean 'stiletto heel'). I am not sure about the 'a fashion' bit.
'despicable person pursuing dagger' is the wordplay.
'despicable person' becomes 'heel' (old-fashioned term for a horrible person).
'pursuing' means one lot of letters go next to another.
'dagger' becomes 'stiletto' (stiletto is a kind of dagger).
'heel' after 'stiletto' is 'STILETTO HEEL'.
'as' is the link.
Can you help me to learn more?
(Other definitions for stiletto heel that I've seen before include "Tall shoe support" , "High slender back to woman's shoe" , "High shoe raiser" , "Pointed item" .)