Definition from Wiktionary, the free dictionary
- 시옷 (siot), a jamo (letter) of the alphabet of the Korean writing system, hangeul; the sibilant phoneme (IPA: /s/)
Usage notes 
Both in the South and North Korean order, ㅅ (s) is the seventh jamo.
Derived terms 
- Coordinate terms
- The sai-siot (사이시옷), genitive marker sometimes placed between a vowel-final syllable and a consonant-initial syllable when forming compounds.