Hangul syllable 씺

It identifies one syllable; the surrounding spelling provides the context.

Hangul combines a starting consonant and a vowel, with an optional ending consonant, into one square syllable block. 씺 decomposes as ᄊ + ᅵ + ᆹ: a starting consonant, a vowel, and an ending consonant part. In keyboard-friendly forms, these components appear as ㅆ, ㅣ, and ㅄ.

Why is 씺 written as one block?

Hangul groups letters into blocks by syllable.

Hangul was created in 1443 to write Korean speech in a dedicated script. Hunminjeongeum, the 1446 text that introduced Hangul, explains the script’s purpose and how initial, middle, and final sounds combine. 씺 follows that system; it is one regular output of the block-building rules, not a separately invented sign.