From The Collaborative International Dictionary of English v.0.48:
Fillet \Fil"let\, n. [OE. filet, felet, fr. OF. filet thread,
fillet of meat, dim. of fil a thread, fr. L. filum. See
Fille a row.]
1. A little band, especially one intended to encircle the
hair of the head.
[1913 Webster]
A belt her waist, a fillet binds her hair. --Pope.
[1913 Webster]
2. (Cooking) A piece of lean meat without bone; sometimes, a
long strip rolled together and tied.
[1913 Webster]
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."
--Shak.
[1913 Webster]
3. A thin strip or ribbon; esp.:
(a) A strip of metal from which coins are punched.
(b) A strip of card clothing.
(c) A thin projecting band or strip.
[1913 Webster]
4. (Mach.) A concave filling in of a re["e]ntrant angle where
two surfaces meet, forming a rounded corner.
[1913 Webster]
5. (Arch.) A narrow flat member; especially, a flat molding
separating other moldings; a reglet; also, the space
between two flutings in a shaft. See Illust. of Base,
and Column.
[1913 Webster]
6. (Her.) An ordinary equaling in breadth one fourth of the
chief, to the lowest portion of which it corresponds in
position.
[1913 Webster]
7. (Mech.) The thread of a screw.
[1913 Webster]
8. A border of broad or narrow lines of color or gilt.
[1913 Webster]
9. The raised molding about the muzzle of a gun.
[1913 Webster]
10. Any scantling smaller than a batten.
[1913 Webster]
11. (Anat.) A fascia; a band of fibers; applied esp. to
certain bands of white matter in the brain.
[1913 Webster]
12. (Man.) The loins of a horse, beginning at the place where
the hinder part of the saddle rests.
[1913 Webster]
Arris fillet. See under Arris.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Fillet \Fil"let\, v. t. [imp. & p. p. Filleted; p. pr. & vb.
n. Filleting.]
To bind, furnish, or adorn with a fillet.
[1913 Webster]