New York (CNN Business) Elon Musk is hoping to put an end to a defamation lawsuit filed against him after he called a rescue worker in Thailand a "pedo guy."

A motion filed by Musk in federal court on Monday argue that Vernon Unsworth, the man Musk insulted, "cannot establish a defamation case just because Mr. Musk insulted him on Twitter and sent a private email to a reporter."

Musk's lawyers argued that the epithet "pedo guy" is commonly used in Musk's home country of South Africa to mean "creepy old man." The term is "aimed at mocking a person's appearance and demeanor, not an accusation of pedophilia," and the insult could be interpreted as an opinion, Musk's attorneys argue. (Under the First Amendment, opinions are often protected speech and typically not considered defamatory.)

A jury trial for the case is scheduled to begin the first week of December. The latest motion asks the judge to rule in Musk's favor before the trial. A response from Unsworth's team is expected next month.

Unsworth, a British caver based in Thailand, was part of a team of rescue workers that saved 12 boys and their soccer coach from a flooded cave in Thailand last summer.

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