Morris Minor Owners Club

i have heard and read pinking mentioned many times, but i havent the foggiest what it means. its probably very obvious, but would someone care to enlighten me to what it actually means

It's a light 'pinging' (or pinking/tinkling) noise - heard when accelerating at lowish engine revs with wide open throttle. Means the ignition is too far advanced - and very damaging to the engine if left for any length of time.