A name given by Nerdanel to one of her youngest children when Fëanor insisted she given them distinct names, though she did not say to which it applied (PM/353). It is a masculinized form of umbar “fate, doom”. Fëanor altered it to the less ominous sounding Ambarto.
Quenya
Umbarto
fated
umbarto
masculine name. Fated
umbar
noun. fate, doom, curse
Umbarto masc. name, "Fated", mother-name (never used in narrative) of Telufinwë = Amras. The ominous name was altered to Ambarto by Fëanor. (PM:353-354)