I. fes ‧ toon 1 /feˈstuːn/ BrE AmE verb [transitive usually passive]
to cover something with flowers, long pieces of material etc, especially for decoration
be festooned with/in something
Malaga was festooned with banners and flags in honour of the king’s visit.
II. festoon 2 BrE AmE noun [countable] formal
[ Date: 1600-1700 ; Language: French ; Origin: feston , from Latin festum ; ⇨ ↑ festive ]
a long thin piece of material, flowers etc, used especially for decoration