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