Silvius
From LSJ
προγράψαντες οὖν τά τε θεωρήματα καὶ τὰ ἐπιτάγματα τὰ χρεῖαν ἔχοντα εἰς τὰς ἀποδείξιας αὐτῶν μετὰ ταῦτα γραψοῦμές τοι τὰ προκείμενα → having therefore written at the beginning the theorems and the postulates that are necessary for their proofs, we will then write out for you the propositions
Silvĭus: ii, m.,
I the name of several kings of Alba Longa, Liv. 1, 3; Verg. A. 6, 769; Ov. M. 14, 610.—Hence the fem. Silvia; v. 1. Rhea.