(The tower of), in Ossian, is Dun-dee, where Dun means a tower. Those circular buildings so common in the Orkney and Shetland Islands, the Hebrides, and all the north of Scotland are duns. Dee is a corruption of Tay, the river on which the city is built; in Latin, Tao-dunum.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
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