He tweeted out a different n-word instead ... and now he's been suspended indefinitely.

Here's the deal ... Focke was watching the Utah Jazz take on the Denver Nuggets on Monday and claims his intention was to tweet about the shooting.

But, something went wrong ... and he sent out the racial slur to his 3,800 followers.

"Shot making in this Jazz-(n-word) game is awesome!" Focke said in the since-deleted tweet. "Murray and Mitchell going back and forth what a game!"

Once he realized what he had done, Focke scrambled to apologize and explain ... saying, "Earlier today I made a horrific error while attempting to tweet about the Denver-Utah game."

"I don’t know how I mistyped, I had (and have) no intention of ever using that word."

"I take full responsibility for my actions. I have been sick to my stomach about it ever since. I’m truly sorry that this happened and I apologize to those I offended."

The Hornets quickly addressed the issue ... suspending Focke indefinitely and launching an investigation into the incident.

"The Charlotte Hornets are aware of the recent social media post by radio broadcaster John Focke. As an organization, we do not condone this type of language."

"John has been suspended indefinitely as we investigate the matter more closely."

To make matter worse ... this is Focke's first season broadcasting for the Hornets.