Agonalia
AGONALIA, in ancient Rome, festivals celebrated on the 9th of January, 17th of March, 21st of May, and 11th of December in each year in honour of various divinities (Ovid, Fasti, i. 319-332). The word is derived either from agonia, "a victim," or from agonium, "a festival."
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)