graffiti (n.)

1851, “ancient wall inscriptions found in the ruins of Pompeii,” from Italian graffiti, plural of graffito “a scribbling,” a diminutive formation from graffio “a scratch or scribble,” from graffiare “to scribble,” ultimately from Greek graphein “to scratch, draw, write”. They are found in many ancient places, but the habit was especially popular among the Romans. Sense extended 1877 to recently made crude drawings and scribbling in public places. (Online Entymology Dictionary)