IPA: /fɛˈstuːnəri/
KK: /fɛˈstuniˌri/
A decorative arrangement of ribbons, flowers, or other materials that hang in a curve or loop, often used for celebrations or decoration.
The hall was adorned with beautiful festoonery for the wedding reception.
Festoonery → It is formed from "festoon" (from French *feston*, meaning a decorative wreath or garland) and the suffix "-ery" (meaning a place or condition of). The word "festoonery" refers to the condition or quality of being decorated with festoons or garlands.
Imagine a place filled with beautiful garlands and decorations — that's what festoonery means, a condition of being adorned with festoons.
No commonly confused words.