First Age
"Boromir" was described by Tolkien as a name "of mixed form"; it combines Sindarin "bor(on)-" 'steadfast' and Quenya "míre" 'jewel'. But the Stewards of Gondor also often bore names "remembered in the songs and histories of the First Age", regardless of meaning, and the name "Boromir" did appear during the First Age in "The Silmarillion". The eleventh steward of Gondor, Denethor I, had as well a son called Boromir who was described as a great warrior. This might have been an inspiration for Denethor II to name his first son.