As used in this chapter, the following terms shall have the meanings indicated:
Any unlawful inscription, word, figure, painting, or other defacement that is written, marked, scratched, drawn, painted or engraved on or otherwise affixed to any surface of public or private property by any graffiti instrument to the extent that graffiti was not authorized in advance by the owner or the occupant of the property, or despite advanced authorization, deemed a public nuisance.