ß - Wikipedia
History Origin. The spelling of 'sz' for the voiceless alveolar fricative ([s]), continuing Proto-Germanic /t/, originates in Old High German, contrasting with the voiceless alveolo-palatal fricative ([ɕ]), continuing Proto-Germanic /s/, spelled 'ss'.. The spelling survives in Middle High German even after the merger of the two phonemes [s] and [ɕ].
DA: 49 PA: 57 MOZ Rank: 50