Illness
Disease
noun
A rapid sickness is an illness or a disease.
This is a jukugo word that uses on'yomi readings, but you haven't seen the へい reading for 病 yet. In fact, this is pretty much the only word it appears in, and on top of that it gets rendaku'd. So here's a mnemonic to help you out:
If you don't treat an illness right away, you might pay (ぺい) with your life. And if you don't die, you'll still have to pay a lot for doctor and hospital fees. Yuck.
がん、急性心筋梗塞、脳卒中のことを三大疾病といいます。
The three major diseases are cancer, heart attack, and stroke.
An update is needed before you can continue but you have more than one WaniKani tab open.
Finish up what ever you are doing on the other tab(s), then close them to continue.
The update will complete automatically once the other tab(s) are closed.