Definition: a wreath, garland, or other ornamental hanging draped between two points
Festoons of lights
As a verb, “festoon” means to hang something in a decorative fashion, or just to decorate in general, as if for a party or celebration.
Why I Looked It Up
In a book about India in the early 20th century:
the twilight passes quickly, festoons of electric light make a dazzle on a hundred tea-tables…