1.A little band, especially one intended to encircle the hair of the head. "A belt her waist, a fillet binds her hair."
2.(Cooking) A piece of lean meat without bone; sometimes, a long strip rolled together and tied. Note: A fillet of beef is the under side of the sirlom; also called tenderloin. A fillet of veal or mutton is the fleshy part of the thigh. A fillet of fish is a slice of flat fish without bone. "Fillet of a fenny snake."
4.(Mach.) A concave filling in of a reentrant angle where two surfaces meet, forming a rounded corner.
5.(Arch.) A narrow flat member; especially, a flat molding separating other moldings; a reglet; also, the space between two flutings in a shaft.
6.(Her.) An ordinary equaling in breadth one fourth of the chief, to the lowest portion of which it corresponds in position.
7.(Mech.) The thread of a screw.
8.A border of broad or narrow lines of color or gilt.
9.The raised molding about the muzzle of a gun.
10.Any scantling smaller than a batten.
11.(Anat.) A fascia; a band of fibers; applied esp. to certain bands of white matter in the brain.
12.(Man.) The loins of a horse, beginning at the place where the hinder part of the saddle rests.