fillet

1. (now rare) A headband; a ribbon or other band used to tie the hair up, or keep a headdress in place, or for decoration.Examples: "In secret shadow, farre from all mens sight: From her faire head her fillet she undight, And laid her stole aside."; "A fillet binds her hair."; ""Know thy own worth, and reverence the lyre," is a line that should be as a fillet bound round the brow—a philactory embroidered on the garments of every son and daughter of Adam distinguished by the possession of that sacred gift, which, whether used or abused, applauded in itself or derided in its possessor, is the highest and the most inalienable distinction humanity ever has or ever can be gifted with, whether bestowed on the highest or the humblest being, in the great mass to which we all belong."archaic

2. (construction) A heavy bead of waterproofing compound or sealant material generally installed at the point where vertical and horizontal surfaces meet.

3. (engineering, drafting, CAD) A rounded relief or cut at an edge, especially an inside edge, added for a finished appearance and to break sharp edges.

4. (UK) A premium cut of meat, especially beef, taken from below the lower back of the animal, considered to be lean and tender; also called tenderloin.Examples: "fillet steak"Synonyms: filetUK

5. (architecture) A thin featureless moulding/molding used as separation between broader decorative mouldings.

6. (architecture) The space between two flutings in a shaft.