Santhos
I have made up "Santhos" somewhen in between the years 2000 and 2002. "Santhos" has been derived from the word "santos", which bears the correct pronunciation. To make its abbreviation perfectly symmetrical, "sts", I have used knowledge of english "th" and put "h" letter behind "t", which have satisfied the demands.
Few years ago I realized that the word has 7 letters and 7 has always been my lucky number. Fate is a poweful witch*.
* Yes, someone may use a different word.