ㅊ

Etymology
The Hunmin Jeongeum Haerye, the treatise introducing the principles behind the Korean alphabet written by its inventor in 1446, explains that this glyph was derived by adding a stroke to  to represent aspiration.

Letter

 * 1) 치읓 (chieut), a jamo (letter) of hangul, the Korean alphabet.

Usage notes

 * ㅊ (chieut) is pronounced as an aspirated alveolo-palatal affricate, i.e. similar to the English ch.