TSADHEH
, or, as commonly anglicized, sadhe [צ; final, ץ].
The eighteenth letter of the Hebrew alphabet, later also used, outside the Hebrew Scriptures, as a number to denote ninety. It is one of the five Hebrew letters that have a different form when used as the final letter of a word.
There is no equivalent to this letter in the English alphabet. It has a strong hissing sound similar to the sound of “ts” in English. In the Hebrew, it appears as the initial letter in each of the eight verses in Psalm 119:137-144.