The Collaborative International Dictionary
Flabellum \Fla*bel"lum\, n. [L. See Flabel.] (Eccl.)
A fan; especially, the fan carried before the pope on state
occasions, made in ostrich and peacock feathers.
--Shipley.
Wiktionary
n. 1 A large fan used for religious ceremony. 2 (context botany zoology English) Any fan-shaped structure.
Wikipedia
A flabellum (plural flabella), in Christian liturgical use, is a fan made of metal, leather, silk, parchment or feathers, intended to keep away insects from the consecrated Body and Blood of Christ and from the priest, as well as to show honour. The ceremonial use of such fans dates back to Ancient Egypt, and an example was found in the tomb of Tutankhamun. A flabellum is also a fan-shaped structure on the fifth legs of horseshoe crabs (Xiphosura).
Flabellumis a genus of marine corals belonging to the family Flabellidae.