嘿
hēi · HSK 7
hey!
👋 sounds exactly like English hey - hēi = hey!
嘿 is mostly the mouth radical 口 on the left plus 黑 hēi (black) on the right giving the sound. The 口 marks it as something spoken, an exclamation you call out to get attention.
嘿 — mouth 口 + black 黑 (phonetic)
嘿 is a phono-semantic compound. The 口 (mouth) radical signals it is an utterance or interjection, while 黑 (hēi, 'black') supplies the sound. It is a modern colloquial exclamation used like 'hey' or to express surprise, not derived from an ancient pictograph.