noun
seriously ill patient; critical case
Refers to a person with a severe or critical illness, often in medical or news contexts.
新型コロナウイルスで重症者数が増えている。
The number of seriously ill patients is increasing due to the novel coronavirus.
彼は事故で重症者として病院に運ばれた。
He was taken to the hospital as a critically injured person after the accident.
軽症者 is the opposite, meaning a mildly ill or lightly injured person.
Compound of 重症 (serious illness) and 者 (person).