Tesla CEO Elon Musk has said he did not intend to accuse a British diver of being a paedophile when he called him "pedo guy" on Twitter.
Vern Unsworth, 64 - who helped rescue 12 Thai boys from an underwater cave in 2018 - has sued Mr Musk for defamation.
In court documents, lawyers for Mr Musk argued that in South Africa, where he grew up, "pedo" is commonly used to refer to a "creepy old man".
The spat began after Mr Unsworth spoke about Mr Musk in a CNN TV interview.
In the interview, Mr Unsworth said the miniature submarine Mr Musk sent to Thailand to help with the rescue would not work and was a publicity stunt.
He added that Musk could "stick his submarine where it hurts".
Mr Musk responded on Twitter by calling him "pedo guy". He later deleted the tweets and apologised after huge outrage.
Mr Unsworth filed a defamation lawsuit against Mr Musk in Los Angeles.
In court filings on Monday, Mr Musk said: "It is synonymous with 'creepy old man' and is used to insult a person's appearance and demeanor, not accuse a person of acts of pedophilia."
"I did not intend to accuse Mr Unsworth of engaging in acts of pedophilia," he added. "In response to his insults in the CNN interview, I meant to insult him back by expressing my opinion that he seemed like a creepy old man."
Mr Musk also said in his court filings that his aide hired a private investigator who "reported that Mr Unsworth associated with Europeans who engage in improper sexual conduct in Thailand".
Mr Unsworth, who lives partly in Thailand with his 41-year-old partner, has denied all accusations of wrongdoing.
His lawyer Lin Wood told the AFP news agency: "Musk's motion is as offensive to the truth and the sworn testimony developed in this case as was his initial false and heinous accusation of paedophilia."
The defamation trial is scheduled for 2 December.
Mr Musk's comments on Twitter have been controversial on other occasions.
In April he reached a settlement with the Securities and Exchange Commission (SEC) over his tweets, which also puts a restriction on his use of Twitter.