Meaning of yán zhòng:
严重
grave; serious; severe; critical
Tā de bìngqíng hěn yánzhòng.
他的病情很严重。
His condition is very grave.
Tā de bìngqíng fēicháng yánzhòng, xūyào mǎshàng zhùyuàn.
他的病情非常严重,需要马上住院。
His condition is very serious and requires immediate hospitalization.
Tā de bìngqíng hěn yánzhòng, xūyào lìjí zhùyuàn.
他的病情很严重,需要立即住院。
His condition is very severe and requires immediate hospitalization.
Zhè cì shìgù fēicháng yánzhòng.
这次事故非常严重。
This accident is very critical.