(noun) A minor surface defect such as, but not limited to, scratches, nicks, dents, scuffs, etc.. Usually used when multiple types of minor blemishes exist on the same surface.
(verb) The act of placing such defects on a surface
Hey Jimmy, quit using that screwdriver to clean that steel plate or you'll knarf it all up!
Originaly part of the philosophical idea, brought about by Sir Jeffery Boivin around the renaissance era, that all parts must have a whole, thus making one side dark and one light. The dark being Knarf and the light being Fwanky. Used often as an insult.
Knarf is a word for telling somebody that they're totally horny for everyone. They just can't seem to give themselves any restrictions for whom they are jerking off to. Child porn is not an untouched subject regarding all those we call Knarf.