n. Graffiti painted in a very high spot.
Piece of "giraffiti" (it was high up) at corner of Bastings and High streets, Northcote: "HOWARD: IT IS UN AUSTRIAN TO TELL LIES".
—Lawrence Money, “Spy,” Sunday Age (Melbourne, Australia), March 10, 2002
Spray paint should become a controlled substance to stop the spread of graffiti and its new, high-altitude cousin "giraffiti,'' says city Coun. Helen Hughes.

At city council meeting Thursday, Hughes asked municipal bureaucrats to work investigating how spray paint could be regulated and controlled.

She said regulations might include the need to have a permit to buy spray paint, or a limit on the number of cans sold at a time, or requirements to store the spray paint behind a counter.

To make any regulations effective, they would have to be enacted across the entire Capital regional district, she said.

Hughes also noted there is also a new phenomena called giraffiti.

It's presumably a combination of the words graffiti and giraffe because Hughes said it involves spray painting a picture or graffiti signature, called a tag, as high as possible off the ground.
—Richard Watts, “Make spray paint a controlled substance to stop graffiti: Victoria councillor,” The Canadian Press, January 04, 2001
1998 (earliest)
Report from week 278:

in which you were asked to take any word from the dictionary, alter it by adding, subtracting, or changing a letter, and supply a new definition.

Fifth Runner-Up: Foreploy: any misrepresentation about yourself for the purpose of obtaining sex. (Greg Oetjen, Lorton)

Fourth Runner-Up: Fortissimoe: the musical moment produced when someone serially slaps the faces of the first-violin section. (Jean Sorensen, Herndon)

Third Runner-Up: Tatyr: a lecherous Mr. Potato Head. (Chuck Smith, Woodbridge)

Second Runner-Up: Doltergeist: a spirit that decides to haunt someplace stupid, such as your septic tank. (David Genser, Arlington)

First Runner-Up: Giraffiti: vandalism spray-painted very, very high, such as the famous "Surrender Dorothy" on the Beltway overpass. (Robin D. Grove, Arlington)
—“The Style Invitational,” The Washington Post, August 02, 1998