Source: Webster's Revised Unabridged Dictionary (1913)

Festoon \Fes*toon"\, n. [F. feston (cf. Sp. feston, It.
festone), prob. fr. L. festum festival. See Feast.]
1. A garland or wreath hanging in a depending curve, used in
decoration for festivals, etc.; anything arranged in this
way.

2. (Arch. & Sculp.) A carved ornament consisting of flowers,
and leaves, intermixed or twisted together, wound with a
ribbon, and hanging or depending in a natural curve. See
Illust. of Bucranium.
Festoon \Fes*toon"\, v. t. [imp. & p. p. Festooned; p. pr. &
vb. n. Festooning.]
To form in festoons, or to adorn with festoons.