SWARTH, sworth, adjective

1. Being of a dark hue; moderately black; tawny.

A nation strange with visage swart.

[I believe swart and swarth are never used in the United States, certainly not in New England. Swarthy is a common word.]

2. Gloomy; malignant. [Not in use.]

SWART, verb transitive To make tawny.

SWARTH