For those of us not up on our Mandarin, what's "four sz" and why is there a word for it?

I am sorry. I was in a big hurry yesterday and posted in haste. I should just delete it. The Chinese word for 'four' is si /szi/. I've never been able to hear the vowel, hearing only the /sz/ which can be sustained without a vowel. I didn't look up its proper Pinyin spelling and fell back on some pseudo romanization scheme. It occurs in the Chinese toponym Sichuan meaning literally 'four rivers'.

Ceci n'est pas un seing.