The Collaborative International Dictionary
Sothiac \So"thi*ac\, Sothic \Soth"ic\, a. Of or pertaining to Sothis, the Egyptian name for the Dog Star; taking its name from the Dog Star; canicular.
Sothiac year, or Sothic year (Chronol.), 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.
Douglas Harper's Etymology Dictionary
as in Sothic cycle, a period of 1,460 years, 1828, from French Sothique, from Greek Sothis, an Egyptian name of the star Sirius. The Sothic year is determined by the heliacal rising of Sirius.
Wikipedia
Usage examples of "sothic".
This length of time was called the Sothic cycle because the Egyptians used Sirius as their reference star and in their language this star was called Sothis.
The pressure need not be quite Sothic if the temperature is raised so that the atoms can move and slip around more easily.
Thus, when, contrary to my express orders, she has wandered abroad during the Sothic period, I have been enabled to trace her movements by the progressive howling of dogs.
The fatal Sothic month which I have learned to regard with horror, commenced on the twenty-third ultimo and does not terminate for another five days.
The Ancient Egyptian civil calendar year was geared to the Sothic year so that both would coincide on the same day/month position once every 1461 calendar years.