Partly Facetious: What actually constitutes defamation?

"There is one Pakistani who should go to court for defamation."
"What brought that on? Oh I see; Prince Harry and his wife have announced they are taking legal action against the Mail on Sunday after the newspaper allegedly unlawfully published one of the Duchess' private letters."
"So the letters are authentic?"
"I would assume so."
"Isn't defamation defined as a charge that is false?"
"Yeah, but then the Prince went on to reference the coverage of Princess Diana and stated that it is his deepest fear that history may repeat itself."
"I ain't a lawyer but there are differences - Princess Diana was hounded by the press wanting her snapshot, she sold copy, while the British media doesn't really like Meghan Markle..."
"You mean coverage versus opinion?"
"That's the way I read it, I could be wrong but the Mail on Sunday has said it will fight the case so I reckon they feel they have a right to publish whatever they want if that is the truth."
"I see, and I reckon you mean The Khan is the most maligned Pakistani and should go to court for defamation - I mean his economic team is assuring him that all is well and yet a section of the media dares say that all is not well and..."
"Don't be facetious, you know as well as I that unemployment is rising as is inflation and the icing on the cake was the recent doubling of the petroleum levy on all oil and products by the economic team..."
"OK, so not that, but there are people who say that The Khan's kitchen cabinet is staffed mainly by non-PTI members."
"Not that either as that just shows that The Khan has acknowledged that his party never had any experts in any sector and..."
"Dear me, anyway before you go on let me tell you that I was not referring to The Khan when I said there is one Pakistani who must go to court for defamation and you will never be able to guess so let me name the person please."
"The non-resident Pakistanis who now surround The Khan..."
"Nope, and as I said you won't ever guess so here goes: its Bushra Bibi and I would urge her to go to court..."
"But our defamation laws are so not cool!"
"OK, so she should get The Khan to strengthen them and then go to court."
"The Khan shuts down television programmes who speak of the state of their marriage." "That simply fuel the rumours. I would urge her to go to court and hopefully the court would impose a penalty on the maligner that would stop future attempts at..."
"But if a tribunal is established..."
"Read my lips: strengthen the defamation laws. That's the best democratic way."