ㅇ

Etymology
Modern usage represents a seventeenth-century merger of the glyph ㅇ, which usually represented a null consonant but sometimes the fricative in Middle Korean, and the now obsolete glyph, which represented. Because a null coda consonant is not written in Korean while appears only at a syllable coda, no ambiguity was created by this merger.

The Hunmin Jeongeum Haerye, the treatise introducing the principles behind the Korean alphabet written by its inventor in 1446, explains that ㅇ was derived from the "outline of the throat", as is visible when pronouncing a vowel or a laryngeal consonant. concurs, as there is no possible source.

Sejong explains that the form of was chosen despite the fact that  is a velar—and thus should theoretically be visually related to the other velar consonants,  and —because "the pronunciation resembles that of ㅇ []", noting that the dialects of some Chinese rime dictionaries have in fact lost initial. (The Korean pronunciation of Chinese also dropped initial, although he does not explicitly give this as a reason.) Ledyard suggests that Sejong derived the nasal letters by removing strokes from the glyphs for the plosives. But the glyph for was ㄱ, from which removing a stroke would provoke confusion with the vowel glyphs  or. According to Ledyard, Sejong thus chose ㅇ as the visual basis of the letter for, both to avoid confusion with vowels and to note the fact that both Sino-Korean and many Chinese varieties dropped initial , while the added stroke on top of ㆁ was regularly derived from to mark the velar nature of the consonant.

Letter

 * , a jamo (letter) of hangul, the Korean alphabet.
 * At the beginning of a syllable, ㅇ (ieung) is not pronounced. At the end, it is a velar nasal, identical to the English ng.

Derived terms

 * (obsolete)