Sabbath is the English rendering of Shabbat (or Shabbath or Shabbos - שבת), which etymologically stems from the root ש-ב-ת, which conveys cessation of activity. A related word in Hebrew is שֶבֶת, which means sitting.
The word does not have any inherent numerical meaning (such as seven), but in rabbinic literature it is used to mean week. The reason, though, is likely its cultural attachment to the seven-day cycle punctuated by the Sabbath at the end.
Ultimately, to answer your question, though, we don't translate it as anything. Most observant Jews actually don't even call it Sabbath. We call it by its Hebrew name, and depending upon one's pronunciation, the most common pronunciations look in English like Shabbos or Shabbat.