Ides, n. pl.

[Fr. ides, It. idi, Sp. idos, idus, Lat. idus, according to Macrobius from the Etruscan iduare, i. q. dividere, to divide, from the root vid, and thus as if the divided or half month, but perhaps more correctly, on account of the long i, from the Gr. ἰδεῖν, to see, and thus the whole visible moon, the full moon.] (Anc. Rom. Calendar.) The fifteenth day of March, May, July, and October, and the thirteenth day of the other months.

☞ Eight days in each month often pass by this name, but only one strictly receives it, the others being called the day before the ides, and so on, backward, to the eighth from the ides.