Shaquille O'Neal Goes Scorched Earth On Dwight Howard, You're Dead To Me!

Shaquille O'Neal is moving on from his longstanding feud with Dwight Howard ... saying he has officially "deleted" his nemesis from his life.

The beef has been well documented over the years ... and initially, it mostly stemmed from Howard taking on the "Superman" nickname, which Shaq was known to use over the course of his Hall of Fame career.

Howard revisited their history during a recent podcast episode ... saying he was so pissed off over it all, he considered showing up at the TNT studios to confront Shaq -- as an old-fashioned beatdown might be the only way to resolve their issues.

The four-time NBA champ got wind of Howard's words ... and unloaded on the guy on social media.

"@DwightHoward the fact u think I care about u is funny, but I won't ever bring your name up again sensitive big man, a jokester that can’t take a joke," he said.

"Won't ever say your name again ever again. Have a great day and now u have been deleted. Have a great day."

Shaq also fired off some hashtags ... adding phrases like "I never cared," "Don't need validation, you do," "You gotta show respect to get respect," and possibly the most harsh -- "Now you're dead to me."

Howard didn't take it sitting down, though ... teeing off in a reply.

"I know you care. Cuz yo insecure ass been hating and talking s*** for 20 years. You to big to be this insecure. I hope you don’t bring my name up again. 52 years old tweeting me.  And still hating. Now all this time you was joking."

Howard also accused Shaq of being jealous of all his sidekicks over the course of his career ... name-dropping guys like Kobe Bryant, Penny Hardaway and Dwyane Wade -- as well as his TNT co-host Charles Barkley.