Magazine to quote Newton over demonstrating attraction (8)
I believe the answer is:
magnetic
'attraction' is the definition.
(magnetic attraction is a kind of attraction)
'magazine to quote newton over' is the wordplay.
'magazine' becomes 'mag' (abbreviation for magazine).
'to quote' becomes 'cite' ('cite' can be a synonym of 'quote').
'newton' becomes 'N' (symbol for the scientific unit of force).
'over' says the letters should be written backwards.
'cite'+'n'='citen'
'citen' backwards is 'netic'.
'mag'+'netic'='MAGNETIC'
'demonstrating' acts as a link.
(Other definitions for magnetic that I've seen before include "Attracting iron or steel" , "What's attractive" , "Drawing" , "attractive result" , "Very attractive or alluring" .)