what is an elven?
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arwen's dad in lord of the rings Her father was Elrond half-elven, a descendant of the Man Tuor.
An elf having both Men and Elves as ancestors. Those who have Elves as ancestors. An elf (plural: "elves") is a type of humanlike supernatural being in Germanic mythology and folklore.
Elrond Elrond Elf
Introduction Introduction Introduction
 Both of his parents, Eärendil and Elwing, were half-elven, having both Men and Elves as ancestors.  Eärendil and Elwing, were half-elven, having both Men and Elves as ancestors.  An elf (plural: "elves") is a type of humanlike supernatural being in Germanic mythology and folklore. 
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Arwen [SEP] Introduction
Arwen Undómiel is a fictional character in J. R. R. Tolkien's Middle-earth legendarium. She appears in the novel "The Lord of the Rings". Arwen is one of the half-elven who lived during the Third Age; her father was Elrond half-elven, a descendant of the Man Tuor, while her mother was the Elf Celebrian, daughter of the Elf-queen Galadriel. In the novel, she marries the Man Aragorn, who becomes King of Arnor and Gondor, thus adding long life and nobility to his dynasty. In Peter Jackson's film adaptation, Arwen is played by Liv Tyler.