Aragorn’s reforged sword is called Andúril in The Lord of the Rings. The name means “Flame of the West” in the fictional Elvish language Quenya.
Andúril is made from the shards of Narsil, the sword that cut the One Ring from Sauron’s hand at the end of the Second Age. Narsil was wielded by Elendil, and it broke when Elendil fell in battle. His son Isildur used the broken sword’s hilt-shard to sever the Ring from Sauron.
The sword is reforged before Aragorn openly claims his royal heritage. Narsil is therefore the original blade, while Andúril is its renewed form. Glamdring belongs to Gandalf, and Sting is Bilbo’s and later Frodo’s short sword, making them plausible but incorrect alternatives.