Six Counties writer bowled over by Peg in lane (7)
I believe the answer is:
ninepin
'peg in lane' is the definition.
(a peg in a bowling lane)
'six counties writer bowled over' is the wordplay.
'six counties' becomes 'NI' (the six counties of Northern Ireland).
'writer' becomes 'pen' (something which writes).
'bowled' becomes 'in' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'over' says the letters should be written backwards.
'ni'+'pen'+'in'='nipenin'
'nipenin' reversed gives 'NINEPIN'.
'by' is the link.
Can you help me to learn more?
(Other definitions for ninepin that I've seen before include "over one goes" , "What bowler tries to hit" , "target to knock over" , "Skittle" , "Type of bowling" .)