Hero of Gondor and one of the Followship of the Ring (LotR/240). This name was also used by one of the Edain, 4th chief of the House of Bëor (S/148) and the 11th ruling steward of Gondor (LotR/1039). This name is a mixture of Sindarin and Quenya elements (LotR/1128), likely [N.] bôr “steadfast” and Q. mírë “jewel”. As pure Sindarin name, a final element S. mîr would have been lenited to -vir, producing *Borovir.

Conceptual Development: In Silmarillion drafts from the 1930s, N. Boromir was given as the name of an Easterling in Beleriand, one of the sons of Bór (LR/134). In The Etymologies, this name is explained as a combination of ON. boron “steadfast” and mīro (a masculinized form of ON. mīre “jewel”), thus ON. Boronmīro > N. Boromir (Ety/BOR, MIR). In this earlier etymology, the preceding n would prevented the mutation of the m. In Silmarillion revisions from the 1950s-60s, this character’s name changed to Borlach (WJ/240).

In The Lord of the Rings, S. Boromir was not longer an ancient name. This may be why Tolkien changed it to a mixed-language name to explain the presence of the m. However, the earlier etymology could have been applicable to (archaic) S. Boromir of the House of Bëor from The Silmarillion.