Page "House of Bëor" Paragraph 8

In early versions of the histories Tolkien stated that the names of the descendants of Bëor were given in Sindarin, and proposed the following meanings ( for the members present at that stage ): Bëor ' follower, vassal ', Bregolas ' fierceness ', Barahir ' fiery lord ', Baragund ' fiery prince ', Belegund ' great prince ', Beren ' bold ', and also Boromir ' steadfast jewel ', though the last was rather the name of Bór's son.

Later, however, Tolkien would write that these names were given in their own language with unknown significance.

Only the meaning of Bëor was preserved, but now it came from the tongue of the Folk.