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Magnēsia, ae, f.,  =  Μαγνησία, a geographical proper name. 
- A.  A country in Thessaly, on the Ægean Sea, Mel. 2, 3, 4; Plin. 4, 9, 16, § 32; Liv. 42, 54, 10; 44, 11, 3. 
- B.  A city in Caria, on the Mæander, now Aineh Bazar, Plin. 5, 29, 31, § 114; Liv. 37, 45, 1; Nep. Them. 10, 2.
- C.  A city in Lydia, on Mount Sipylus, now Manisa, Plin. 2, 91, 93, § 205; Liv. 36, 43, 9; 37, 10, 12; 37, 11, 3.
 Hence,
- A.  Magnēsĭus, a, um, adj.,  =  Μαγνήσιος, of or belonging to Magnesia, Magnesian: Magnesia flumine saxa, i. e. of the magnet, Lucr. 6, 1064; v. 1. magnes.
- B.  Magnessa, ae, adj. f.,  =  Μάγνησσα, a Magnesian woman: Magnessam Hippolyten dum fugit abstinens, Hor. C. 3, 7, 18.
- C.  Magnētarches, ae, m.,  =  Μαγνητάρχης, the chief magistrate of the Magnesians, Liv. 35, 31, 11; 35, 39, 6. 
- D.  Magnētes, um, m.,  =  Μάγνητες, the Magnesians, Liv. 33, 32; 34; 35, 31: (lapis) Magnetum quia sit patriis in finibus ortus, Lucr. 6, 909; Luc. 6, 385: Magnetas adit vagus exsul, Ov. M. 11, 408.
 In sing.: Magnes, ētis, m., a Magnesian: Dionysius Magnes, Cic. Brut. 91, 316.
 As adj., Magnes campus, Val. Fl. 2, 9.
- E.  Mag-nētis, ĭdis, adj. f.,  =  Μαγνῆτις, of or belonging to Magnesia, Magnesian: cur umquam Colchi Magnetida vidimus Argo? (because built at Pagasae, in Magnesia), Ov. H. 12, 9.