Spike article about king (6)
I believe the answer is:
pierce
'spike' is the definition.
(I know this)
'article about king' is the wordplay.
'article' becomes 'piece' (article can mean a thing or item).
'about' means one lot of letters goes inside another.
'king' becomes 'R' (abbreviation for rex, king in Latin).
'piece' enclosing 'r' is 'PIERCE'.
(Other definitions for pierce that I've seen before include "Make hole in using pointed instrument" , "Cut a way through" , "Possibly drill" , "Prick" , "Penetrate as with sharp object" .)