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amb-urbĭum, ii, n. [urbs], the expiatory procession round the city of Rome, at which sacrifices were offered (v. the preced.); Serv. ad Verg. E. 3, 77; Paul. ex Fest. p. 17 Müll.: lustrata urbs, cantata carmina, amburbium celebratum, ambarvalia promissa, Vop. Aur. 20 (described in Luc. 1, 592 sq.).