lustrum, i, n. 2. luo, a purificatory sacrifice, expiatory offering, lustration, made by the censors for the whole people once in five years, after completing the census, and in which a swine, a sheep, and a bull were offered (suovetaurilia): lustrum condere, to make the lustral sacrifice: lustrum condidit et taurum immolavit, Cic. de Or. 2, 66, 268: censu perfecto edixit, ut omnes cives Romani in campo primā luce adessent. Ibi exercitum omnem suovetaurilibus lustravit: idque conditum lustrum appellatum, quia is censendo finis factus est, Liv. 1, 44; 3, 24; cf. id. 35, 9; 38, 36; 42, 10. The census could also be taken without being followed by a lustrum, Liv. 3, 22, 1; 24, 43, 4: sub lustrum censeri, at the close of the census, when the lustrum should begin: sub lustrum censeri, germani negotiatoris est (because these were usually not in Rome, and were included in the census last of all), Cic. Att. 1, 18, 8.

—Being a religious ceremonial, the lustrum was sometimes omitted, when circumstances seemed to forbid it: census actus eo anno: lustrum propter Capitolium captum, consulem occisum, condi religiosum fuit, Liv. 3, 22, 1. Hence in part, doubtless, must be explained the small number of lustra actually celebrated; thus, A. U. C. 296: census perficitur, idque lustrum ab origine urbis decimum conditum ferunt, Liv. 3, 24, 10.

— Transf. A propitiatory offering: quinto die Delphis Apollini pro me exercitibusque et classibus lustra sacrificavi, Liv. 45, 41, 3.

— A period of five years, a lustrum (because every five years a lustrum was performed). In gen.: cujus octavum trepidavit aetas Claudere lustrum, Hor. C. 2, 4, 24; Ov. Tr. 4, 10, 78; Mart. 10, 38, 9.

— As the period of taxation, in reference to the imposition of duties, Varr, L. L. 6, 2, 11: hoc ipso lustro, Cic. Att. 6, 2, 5: superioris lustri reliqua, id. Fam. 2, 13, 3.

— In gen., a period of several years; of four years (of the Julian calendar), Ov. F. 3, 163; cf. Plin. 2, 47, 47, § 122: ingens lustrum, the grand lustrum, a hundred years, at the end of which the ludi saeculares were celebrated, Mart. 4, 1, 7.

— From the time of Domitian, the Capitoline games, recurring every fifth year, Suet. Dom. 4; Censor. de Die Nat. 18; cf. Stat. S. 4, 2, 60: certamine Jovis Capitolini lustro sexto, Inscr. Grut. 332, 3; called lustri certamen, Aur. Vict. Caes. 27, 7.

— Hectoris Lustra (not Lytra), title of a tragedy of Ennius; v. Trag. Rel. p. 28 sq. Rib.; Vahl. Enn. p. 113 sq.

— The term of a lease: priore lustro, Plin. Ep. 9, 37, 2.