English and Scottish, very rare. A female correspondent [MCT] with that name has only ever found one other woman with the name but has heard of one man bearing it. The name derives in this case from a mountain near Mull, with a Gaelic meaning "big hill" [Mhour bheign].
A second correspondent [CK] has details of an émigré to New Zealand from Scotland named Morven. In this case the name is from the mountain on the borders of two Aberdeenshire parishes of Logie Coldstone and Glenmuick, Tullich & Glengairn.
Morven is the name given to Fingal's kingdom by James Macpherson [1736-1796] in his Ossiniac poems. He based it on the name of an area of north Argyll, Scotland, Morvern, or a'Mhorbairne in Gaelic. Other mountains in Scotland with the same or similar names may be found north of Inverness and in Perthshire.