Filbert \Fil"bert\, n. [Perh. fr. fill + bread, as filling the bread or husk; cf. G. bartnuss (lit., bread nut) filbert; or perh. named from a St. Philibert, whose day, Aug. 22, fell in the nutting season.]

(Bot.) The fruit of the Corylus Avellana or hazel. It is an oval nut, containing a kernel that has a mild, farinaceous, oily taste, agreeable to the palate.

Note: In England filberts are usually large hazelnuts, especially the nuts from selected and cultivated trees. The American hazelnuts are of two other species.

Filbert gall (Zo["o]l.), a gall resembling a filbert in form, growing in clusters on grapevines. It is produced by the larva of a gallfly (Cecidomyia).

Source: Webster's Revised Unabridged Dictionary (1913)