from the GNU version of the Collaborative International Dictionary of English
- adj. the Egyptian year of 365 days and 6 hours, as distinguished from the Egyptian vague year, which contained 365 days. The Sothic period consists of 1,460 Sothic years, being equal to 1,461 vague years. One of these periods ended in July, a. d. 139.
Sorry, no etymologies found.