I never realized that was meant to be the Klingon word for, well Klingon. I thought it was just 'language' or something.
I never heard it pronounced, nor have I actually tried to sound it out before, but I hear it now.
The "ngan" portion is an identifier for a particular people/person, similar to the Klingon words for a Romulan person (romuluSngan) and a Terran person (teraSngan) spoken in STV:TFF (1:09 onward):
Yep, I think maybe we heard it mentioned by name in Discovery's pilot ("Vulcan Hello"/"Battle of the Binary Stars"), as they went to great lengths to get the language right, even so far as changing the more common pronunciation of "Kahless" to sound like (apparently correct) "Kay-LESH".
I remember there was a big kerfuffle over this when the pilot aired, only to be confirmed that that was the correct pronunciation of the name, and literally everyone else that ever spoke the name from the beginning (including Kahless himself in TNG's "Rightful Heir") got it wrong! I just initially chalked it up to the actors not being able to speak properly through all the heavy face prosthetic they were forced to wear in the beginning of that show.![]()
Yes, I was one of the ones who pointed this out about Kahless. But people who were complaining about it didn't care even when the facts were brought up. It's funny how that works.

Kor