What name does John 21 use for the sea where the risen Jesus appeared to seven disciples?

Answer: Sea of Tiberias

By the Sea of Tiberias (the Sea of Galilee), Jesus revealed himself to Peter, Thomas, Nathanael, the sons of Zebedee and two others.

“Later, by the Sea of Tiberias, Jesus again revealed Himself to the disciples. He made Himself known in this way: Simon Peter, Thomas called Didymus, Nathanael from Cana in Galilee, the sons of Zebedee, and two other disciples were together.”— John 21:1-2 (BSB)