Hangul Syllable Gget

In a Korean IME, enter ㄲ, ㅔ, then ㅌ.

These are compatibility jamo, separate from the conjoining jamo ᄁ, ᅦ and ᇀ—the forms that join in a syllable block. NFC recomposes that conjoining sequence as 껱; NFC alone does not turn ㄲㅔㅌ into the same block.

Does 껱 mean anything by itself?

No fixed meaning; it is a syllable, not a word. A Hangul block represents one syllable in Korean spelling. 껱 can form part of a word, but alone it names no thing and carries no fixed reaction.

Where did Hangul blocks come from?

They belong to Hangul, a writing system created for Korean.

The first recorded account appears in the Sejong Annals, a royal chronicle: an entry in 1443 says King Sejong created 28 letters. The 1446 book 훈민정음 explains the new script and how consonant and vowel letters combine into syllables. Hangul made it easier to write Korean speech with letters suited to its sounds rather than relying on Chinese characters alone.

Hangul syllables sit in square blocks that can resemble Hanja, Chinese characters also used in Korean. Hangul letters were not directly derived from Han characters. After 1894, names such as 국문 and 국서 became common as Hangul was framed more strongly as Korea's national writing system. Japanese kana is a separate adaptation of Han characters, not an ancestor of Hangul.