guilloche

noun

1. A fine engraved pattern of spirals, intertwining bands, etc.

   “A railroad right-of-way, straight across the Balkan Peninsula, conceded in Cyrillic and Arabic script all woven in and out of the loveliest green guilloche by the no-longer-quite-unabsorbed entity of East Roumelia.”

2. The tool used to create such work.

verb

1. (transitive)To decorate with intersecting curved lines.