'Graffiti' definitions:

Definition of 'graffiti'

From: WordNet
noun
A rude decoration inscribed on rocks or walls [syn: graffito, graffiti]

Definition of 'Graffiti'

From: GCIDE
  • Graffiti \Graf*fi"ti\, n. pl. [It., pl. of graffito scratched]
  • 1. Inscriptions, figure drawings, etc., found on the walls of ancient sepulchers or ruins, as in the Catacombs, or at Pompeii. [1913 Webster]
  • 2. any writings or drawings on a surface in a public place, placed there without authorization of the owner of the object on which it is written. Such graffiti are usually unwelcome, and are considered as form of vandalism. [PJC]