Afon Derwent (Swydd Derby): Gwahaniaeth rhwng fersiynau

Mae Derwent yn deillio o enw afon [[Brythoneg|Frythoneg]] *Deruentiū, wedi'i Ladineiddio fel ''Deruentiō'', sy'n golygu "(Perthyn/Yn ymwneud â'r) Goedwig Coed Derw"; goroesodd hen enw'r afon mewn barddoniaeth Gymraeg ganoloesol, megis [[Pais Dinogad]] ynghlwm wrth y gerdd fwy [[Y Gododdin]], fel ''Derwennydd''.<ref>Xavier Delamarre, ''Dictionnaire de la langue gauloise'', 2il arg. (Paris, 2003), tud. 141</ref><ref>R. G. Gruffydd, "Where was Rhaeadr Derwennydd (Canu Aneirin line 1114)?', yn ''Celtic Language, Celtic Culture: A Festschrift for Eric P. Hamp'', gol. A. T. E. Matonis a D. F. Melia (Van Nuys, Cal., 1990), tud. 261-6.</ref><ref>T. M. Charles-Edwards, ''Wales and the Britons, 350-1064'' (Rhydychen: Oxford University Press, 2013), tud. 369-70</ref><ref>{{Cite book | last = Ekwall| first = Eilert| author-link = | last2 = | first2 = | author2-link = | title = The Concise Oxford Dictionary of English Place Names| place= Rhydychen| publisher = Clarendon Press| origyear = 1936| year = 1960| page = [https://archive.org/details/conciseoxforddic0000ekwa/page/143 143] | volume = | edition = 4ed | url = https://archive.org/details/conciseoxforddic0000ekwa| doi = | id = | isbn = 0-19-869103-3 | postscript = <!--None-->}}</ref>