呃

Mouth radical on the left - pictograph of an open mouth. Indexes 呃 in the noises-from-the-mouth family with 吃, 喝, 啊, 嗯, 哦. Marks 呃 as a sound made vocally, fitting for an interjection or a hiccup. Most onomatopoeic and exclamatory characters in the script live under this radical.

Right side 厄 supplies the sound (è, exact match). 厄 itself depicts a person crouched under an overhanging cliff - danger, narrow escape. Same phonetic appears in 扼 to grip, 轭 yoke. In 呃 the cliff-pinch image distantly suggests a constricted throat producing a stifled sound - an apt picture for a hiccup.