fret¹ / fret/ • v. (fret·ted, fret·ting) 1. [intr.] be constantly or visibly worried or anxious: she fretted about the cost of groceries | I fretted that my fingers were so skinny. ∎  [tr.] cause (someone) worry or distress.2. [tr.] gradually wear away (something) by rubbing or gnawing: the bay's black waves fret the seafront. ∎  form (a channel or passage) by rubbing or wearing away. ∎  [intr.] flow or move in small waves: soft clay that fretted between his toes.fret² • n. 1. Art & Archit. a repeating ornamental design of interlaced vertical and horizontal lines, such as the Greek key pattern.2. Heraldry a device of narrow diagonal bands interlaced through a diamond.• v. (fret·ted, fret·ting) [tr.] [usu. as adj.] (fretted) decorate with fretwork: intricately carved and fretted balustrades.fret³ • n. each of a sequence of bars or ridges on the fingerboard of some stringed musical instruments (such as the guitar), used for fixing the positions of the fingers to produce the desired notes.• v. (fret·ted, fret·ting) [tr.] [often as adj.] (fretted) 1. provide (a stringed instrument) with frets.2. play (a note) while pressing the string down against a fret: fretted notes.DERIVATIVES: fret·less adj.

frets

fret, frette, fretwork.
1. Meander, or band-like ornament of shallow short fillets touching each other at right angles, called variously angular guilloche, Greek key, or lattice, depending on the type. If some fillets are set diagonally it is called Chinese fret, found in Chinoiserie and Regency work.

2. Trelliswork.

3. Any interlacing raised work.

4. Complex patterns of ribs on a Gothic vault.

5. Net-like forms, as in tracery.

fret1 †devour OE.; gnaw; also fig. XII; chafe, irritate, vex XIII. OE. str. vb. fretan = MLG., MDu. vrēten (Du. vreten), OHG. frezzan, (G. fressen), Goth. fraïtan; f. Gmc. *fra- FOR-1 + *etan EAT.
Hence as sb. XV.

fret2 (chiefly in pp. fretted) †adorned with interlaced work XIV; adorned with carved or embossed work XVII. prob. f. OF. freter, rel. to frete trellis, interlaced work (mod. frette), of unkn. orig.
So sb. XIV. prob. — OF. frete. Comp. fretwork XVIII.

fret3 (mus.) bar of wood, etc., to regulate the pitch in some stringed instruments. XVI. of unkn. orig.