yarn bomb noun 1verb 1forms 3 noun1 •A decorative knitted yarn item, placed on a public structure as a form of graffiti or street art.The damaged yarnbombs are currently being repaired and re-installed – it is hoped that this time the artworks will be there to stay. — 2022 verb1 •To cover (a public structure) with decorative knitted yarn, as a form of graffiti or street art. formsyarn bombed · yarn bombing · yarn bombs