False friends - words that sound like cognates but aren't, are the bane of the language learner. One that American students of Russian get hung up with all the time is "нормально" (normal'no), which sounds like the English "normal" and many American students use to mean "typical", but which actually means "pretty good" in Russian.
In Chinese, the word for "kiss" is "親嘴" (chin zui), but the slang version is "親親" (chin chin). There is even an export company named Chin Chin with two interlocked hearts as its logo.
In Japanese, the slang word for male member is "チンチン", also pronounced "chin chin".
This must have caused quite a bit of mirth and misunderstanding over the years, especially since the English name of the Chinese company is "King Lucky". o.O
Now, the proper French version of "Cheers" for a toast is "Salut", but informally, they also have an onomatopoeic toast to mimic the sound of full glasses clinking. "Chin Chin".
I'd advise French ladies on a business dinner with a bunch of traditional Japanese businessmen to stick to "Salut" when asked what you say when toasting in French. Unless those ladies like seeing their younger companions trying to suppress a snicker while the older ones turn beet red.