What 훰 means
It contributes a syllable; the whole word carries the meaning.
Hangul is the Korean writing system, and its letters combine into syllable blocks. 훰 brings together the starting consonant ㅎ, the vowel ㅝ, and the ending consonant ㅁ; ㅝ is formed from ㅜ + ㅓ.
The Sejong Sillok (the Annals of King Sejong), a royal chronicle, first mentions Hunminjeongeum, a guide to Hangul, in 1443. The 1446 guide explained Hangul's sounds and how its letters form syllable blocks, making writing easier to use. 훰 follows that same rule.
Questions people ask
1Why does 훰 show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type 훰
훰\D6F0Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.