What ㅞ means
Press ㅜ, then ㅔ; on QWERTY, that is N, then P.
On the common two-set Korean keyboard, the input method editor combines those two vowel keys into ㅞ; the vowel does not have its own key. It is a compound vowel made from ㅜ and ㅔ and is romanized “we.” Add the silent initial ㅇ to make 웨, a complete syllable block; the surrounding word supplies its meaning.
Hangul was designed as a sound-based writing system for Korean, with letters arranged into syllable blocks. The first record of Hunminjeongeum, the name for the new script, is dated 1443; its explanatory book followed in 1446. The compound-vowel structure of ㅞ fits that system.
Why does ㅞ appear outside a syllable block?
It is a standalone, spacing form of a Korean vowel letter.
Hangul jamo are the letters that combine to form syllable blocks. The compatibility jamo ㅞ is designed to stand by itself; the related conjoining jamo ᅰ is designed to join other letters in a syllable. Unicode normalization forms NFKC and NFKD can change ㅞ into ᅰ, while a font or text shaper may place ᅰ inside a syllable block. The intended vowel remains the same.
Technical or language-learning; by itself, ㅞ is a vowel letter rather than a complete Korean syllable.
Don't confuse it with
2Questions people ask
1Why does ㅞ 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 ㅞ
ㅞ\315ECodes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.