Airsickness is the name of that plane-motion feeling — the noun. If airsick is “I feel that way,” airsickness is “the thing that happens to you.” You take tablets for airsickness; a rough flight can cause airsickness; a notice might warn of airsickness. It is a little more formal than just saying you feel sick, because it names the condition, but families still use it in everyday talk. Same idea as seasickness or carsickness. Though actually, on a long flight you can feel wretched for many reasons — pressure in the ears, bad food, fear — and people still dump them all under this word. Strictly, it is the motion.

暈機、暈機的不適