sǐ shēng
life or death
critical (event)
sì shēng
the four tones of classical Chinese phonetics, namely: level or even tone 平聲|平声, third tone 上聲|上声, fourth tone 去聲|去声, entering tone 入聲|入声
the four tones of modern standard Chinese pronunciation, namely: First or high level tone 陰平聲|阴平声, Second or rising tone 陽平聲|阳平声, Third or low-falling-raising tone 上聲|上声, Fourth or falling tone 去聲|去声