according to Festus (254) this was the earlier name of the collis Quirinalis, derived from agere 'to offer sacrifice,' but this was probably simply an invention of the antiquarians (Jord. i. I. 180; Walde, Etym. Worterb. s.v.). Cf. Fest. 10, where an even more absurd suggestion is made, that agonus=mons.