Real Dictionary

fret
countable noun: The frets on a musical instrument such as a guitar are the raised lines across its neck.
verb: If you fret about something, you worry about it.

fret in American English 1
to eat away; gnaw
intransitive verb: to feel or express worry, annoyance, discontent, or the like
noun: an irritated state of mind; annoyance; vexation
transitive verb: to torment; irritate, annoy, or vex

fret in American English 2
an ornamental net or network, esp. one formerly worn by women as a headdress
to ornament with a fret
noun: an interlaced, angular design; fretwork
transitive verb: to ornament with a fret or fretwork

fret in American English 3
any of several narrow, lateral ridges fixed across the fingerboard of a banjo, guitar, mandolin, etc. to regulate the fingering
to furnish with frets
noun: any of the ridges of wood, metal, or string, set across the fingerboard of a guitar, lute, or similar instrument, which help the fingers to stop the strings at the correct points
transitive verb: to provide with frets

fret in British English 1
noun: a state of irritation or anxiety
verb: to distress or be distressed; worry

fret in British English 2
noun: a repetitive geometrical figure, esp one used as an ornamental border
verb: to ornament with fret or fretwork

fret in British English 3
noun: any of several small metal bars set across the fingerboard of a musical instrument of the lute, guitar, or viol family at various points along its length so as to produce the desired notes when the strings are stopped by the fingers

fret in British English 4
noun