The word yuon is probably the most controversial four-letter word you could utter in Phnom Penh at the moment.
It has been used by opposition politicians to whip up anti-Vietnamese fervour to win support. It has drawn fire from Hanoi and on Sunday yuon was chanted with venom as demonstrators torched a monument marking Cambodian-Vietnamese 'friendship'.
But for such a loaded term and one that can inspire even bloodshed, it is intriguing that no one seems to be able to give you a definitive meaning.
'It means something worse than dog, something worse than what black men in the US are called,' said Nguyen Van Duc, a trader on the Vietnamese-Cambodia border. 'It hurts and when people say it, they are often aggressive.
'I have had people call me yuon and spit on the ground at my feet. You have to learn to ignore it if you want to do business. It is part of life.' To Nguyen Ngoc Sanh, president of the Vietnamese Association in Phnom Penh, it means a form of 'savage'.
'It means people who come from the forest. It is a very low word.' But for Sam Rainsy, the politician who has used it so loud and frequently before crowds of Cambodian peasants during his unsuccessful election campaign, it means, remarkably, only that some-one is from Yunnan, China.