from The Century Dictionary.
- noun A name applied to diseases characterized by a lack of pigment in integumental structures, as albinism, vitiligo, or canities.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun pathology
Sorry, no etymologies found.
The leader of the group had achromatosis (albinism), they were riding horses and had guns (which could be mistaken with thunder at the time, sound-wise).