Ambarto
From Tolkien Gateway
Ambarto was a Quenya mother-name given to Amras, twin son of Fëanor by Nerdanel, his mother. Initially, both twins were called Ambarussa so their father insisted on having different names. Nerdanel changed one of the names, without clearly deciding which, to Umbarto, which meant, prophetically, "the fated". Because of its meaning, Fëanor had quickly urged Nerdanel to change it to Ambarto, but while she relented, she said that nevertheless Umbarto would be its true form.