Jack Black explains what the D in Tenacious D actually stands for

The meaning behind the comedy rock duo's name has come to light.

Fans of the 'mock rock' duo made up of Jack Black and Kyle Gass are shocked to learn the meaning behind the name.

Talking to Bill Simmons of Grantland, Black revealed the name came from basketball commentary.

The actor shared that the name came from NBA commentator Mark Robert who would use 'tenacious defense!' to praise a team's defending.

"We were deep into the lakey lakes (LA Lakers) in the late 80s and early 90s, and we were jamming a lot at Kyle's apartment and watching basketball and jamming and getting high, and we were thinking 'what would be the best name for a band?'

"And for some reason we were laughing so hard at the idea of a band being called Tenacious D."

He continued: "I don't even know if he ever said the word 'D', I think we might have made that abbreviation for him, but yeah I think we were just really stoned..." 

Well, you learn something new!

Fans on Reddit reacted to the story, one saying: "So their name is just a tribute?"

Another wrote: "The greatest song in the world is Beelzeboss."

Originating in 1994, the duo have rocked out several hits, including Tribute, The Ballad of Hollywood Jack and the Rage Kage, and The Metal.

Tenacious D have appeared in several films such as Bi-Dome and Shallow Hal, as well as the animation hit Kung Fu Panda, in which Black stars as the lovable Po and Gass as KG Shaw.