咳
hāi , ké · HSK 5
cough
😮💨 口 mouth + 亥 (hāi) phonetic = mouth-sound: cough or sigh
Left radical 口 marks it as a mouth-sound. Right side 亥 lends the hāi reading. Two pronunciations split the meanings: hāi for a sigh, ké for a cough.
咳 — mouth 口 + child 亥
A phono-semantic compound: 口 (mouth) gives the meaning, since coughing comes from the mouth, while 亥 supplies the sound. Originally the character could mean a child's laugh (read hāi), but its dominant modern sense is 'to cough' (ké).