cough, clear throat
咳 centers on the act of coughing or clearing the throat, a sudden expulsion of air from the mouth.
咳 combines 口 (mouth) with 亥, which likely contributes the sound. The character expresses sounds made with the mouth, specifically coughing.
The mouth 口 beside 亥: imagine a person making a hacking sound from their mouth, like a cough.
For カイ, picture a person coughing so hard they say 'kai!' as they clear their throat: kai -> カイ.
cough; coughing; tussis
clearing one's throat; cough
cough medicine; cough syrup; cough lozenge
to cough violently; to have a coughing fit
whooping cough; pertussis
cough; coughing
pulmonary tuberculosis (in traditional Chinese medicine)
to have a cough; to cough
to have a coughing fit; to sob convulsively
to cough; to clear one's throat
to cough
cough etiquette; coughing etiquette
dry cough; hacking cough
cough; hawking
to meet someone in person; to have the pleasure of meeting
cough suppression
cough suppressant; antitussive drug; cough medicine
cough suppressant; antitussive drug; cough medicine