fret ‧ work /ˈfretwɜːk $ -wɜːrk/ BrE AmE noun [uncountable]
[ Date: 1600-1700 ; Origin: fret 'cut patterns' (14-21 centuries) (probably from Old French frete ; ⇨ ↑ fretted ) + work ]
patterns cut into thin wood, metal etc or the activity of making these patterns