Mona, Called of the Greekes Monna, is an yle nighe to Brytaine, puissaunt of people in the time of Cornelius Tacirus. where they that fled from the Romaines were succoured: I suppose it to be the yle now called Man, and not Anglesey, for as much as that is ioyned to Brytaine. There is also an other yle of that name in the riuer of Rhene, nigh to Friseland, and not only nighe to Britaine.
Lewis and Short: Latin dictionary
Mŏna, ae, f., = *mo/na, the name of two islands. I.The Isle of Man, near Britain, Caes. B. G. 5, 13.—II.The Isle of Anglesea, Tac. A. 14, 29; id. Agr. 14; 18; Plin. 2, 75, 77, 187.