'narrow-toothed' originates from the combination of 'narrow' and 'toothed', where 'narrow' meant 'of small width' and 'toothed' referred to having teeth.

The term 'narrow-toothed' has remained relatively unchanged in its usage, consistently describing objects with closely spaced teeth.

Initially, it meant 'having narrow teeth', and this meaning has largely remained the same in modern usage.