Final answer:
Faramir most resembles Boromir as the successor to the stewardship of Gondor in Tolkien's works, taking over the role after Boromir's and Denethor's deaths and serving King Aragorn loyally.
Step-by-step explanation:
The character in J.R.R. Tolkien's works that most resembles Boromir in terms of his role as the successor to the stewardship of Gondor is Faramir. Faramir is Boromir's brother and also the son of Denethor, the Steward of Gondor. While Boromir was the favored son and his father's choice as successor, it is Faramir who ultimately takes on the responsibility of stewardship after the deaths of both Boromir and Denethor. Unlike Boromir, Faramir does not fall prey to the temptation of the Ring, showcasing his strength of character. Additionally, the stewardship role passes to Faramir because Aragorn, the rightful heir to the throne of Gondor, becomes the king, and Faramir serves him loyally as Steward.