Miruvor is a reviving cordial made by the Elves.
It renews the strength of the drinker and is warm and fragrant. It is consumed at festivals. Both the Dúnedain and the Orcs possessed drinks with similar properties, but miruvor was known to be the most potent of these cordials. Elrond gave Gandalf some miruvor before The Fellowship left Rivendell. Gandalf then passed this on to the members of the Fellowship as needed- first on Caradhras, next when they stopped to rest, and lastly just inside the gates of Moria.
According to works of Tolkien that tell of much earlier times, miruvor was the cordial of the Valar. "Miruvórë" however was the original term used there.