Mount Gundabad is a mountain at the northern end of the Misty Mountains.
According to the Dwarves, Durin the Deathless, eldest of the Fathers of the Dwarves, awoke at Mount Gundabad in the north of the Misty Mountains shortly after the Awakening of the Elves. Mount Gundabad remained a sacred holy site to the Dwarves ever after and a meeting place with the other Fathers of the Dwarves.
In the Third Age, the Orcs of Angmar claimed it as their capital, which was one of the reasons for the Dwarves' special hatred of this people. After the fall of Angmar Gundabad remained an Orc stronghold, until it was cleaned of Orcs during the War of the Dwarves and Orcs. But the Orcs repopulated it over the next two hundred years, although after the Battle of Five Armies, there probably weren't as many.
Mount Gundabad was the rally point of the armies of Bolg the Goblin chieftain, who would later go on to fight the Battle of Five Armies.
Gundabad is a Khuzdul word of unknown meaning. The first element is probably Gund, meaning "excavated tunnel". ( In Hindi Gundabad means city of villians.)