Hangul syllable dwels

It is a Korean syllable block, not a complete word. Its Hangul jamo—the letter pieces used to build Korean syllables—are ㄷ + ㅞ + ㄽ: a starting consonant, a vowel, and a final pair of consonants. That shows how the syllable is built; the surrounding word or sentence supplies the intended meaning.

King Sejong designed Hangul to make reading and writing Korean easier for people who struggled with systems that used Chinese characters, such as Idu, Gugyeol and Hyangchal. Hangul’s earliest surviving official creation record is from late December 1443; the explanatory Hunminjeongeum manuscript, a guide to the new letters, was completed in September 1446. Those dates concern Hangul as a script, not an attestation of this exact syllable.

Hangul appeared in Buddhist and Confucian translations, practical books, letters and labels. It became the official national writing system in 1894, lost that status under Japanese rule in 1910, and later became a focus of Korean language and national identity.

How do I type 뒔?

A Korean IME can build it from the standard key sequence. On the standard Dubeolsik two-set keyboard layout, switch your input method editor (IME) to Korean and type e n p f t: e makes ㄷ, n plus p builds ㅞ, and f plus t builds ㄽ. The IME commits the result as 뒔.

Unicode represents the same syllable either as one precomposed block or as three conjoining jamo, ᄃ + ᅰ + ᆳ. During input, an app may show the pieces separately before combining them. Fonts choose how the jamo sit inside the square block, so the same character can look different while the text remains the same.