What title did J.R.R. Tolkien give the large eagle who rescues Gandalf from Orthanc?

J.R.R. Tolkien calls the eagle who rescues Gandalf from Orthanc Gwaihir the Windlord. Gwaihir carries Gandalf away from the tower of Isengard after Saruman imprisons him there.

In The Fellowship of the Ring, Gwaihir arrives after Gandalf sends a message through the moth-like messenger associated with the eagles. The eagle bears Gandalf to safety, first taking him to Edoras. Gwaihir later carries Gandalf again after the wizard’s battle with the Balrog, bringing him to Lothlórien.

Gwaihir is distinct from Thorondor, the greatest eagle of the First Age, and from Landroval, another great eagle who participates in the rescue of Frodo and Sam after the destruction of the Ring. Tolkien’s eagles are powerful allies, but they do not simply replace the Fellowship’s journey by flying everyone to Mordor.