Lewis & Short

Septĭmontĭum, ii, n. [septem-mons].

  1. I. The circuit of the Seven Hills, the place upon which the city of Rome afterwards stood, Varr. L. L. 5, § 41 Müll.; Fest. s. v. sacrani, p. 321 ib.; and Becker, Antiq. 1, p. 122 sq.
  2. II. The feast of the Seven Hills, celebrated at Rome in December, in commemoration of the enclosing of all the seven hills within the circuit of the city, Varr. L. L. 6, § 24 Müll.; Fest. pp. 341 and 348 ib.; Tert. Idol. 10; id. ad Nat. 2, 15; Pall. Dec. 1; cf. Plutarch. Q. Rom. 68.