In 2373, during the Federation-Klingon War, Federation forces forced the Klingons to retreat from Ganalda IV. Orderly Kirby on Ajilon Prime theorized this loss to be responsible for the Klingons' increased bloodlust. (DS9: "Nor the Battle to the Strong"; DIS: "Magic to Make the Sanest Man Go Mad")
This planet was only mentioned in dialogue.
"guh-NULL-dah" was the pronunciation for this planet's name from the script pronunciation guide. 
According to the non-canon Top Secret Security Review-31 Command from the Star Trek Into Darkness viral website AreYouThe1701.com, this planet was a Federation colony in the alternate reality that was threatened with being attacked by a Klingon fleet in 2259. Admiral Alexander Marcus considered sending the starship USS Vengeance to the defense of this colony.