Meaning of xū:
xū
嘘
Verb
to exhale slowly; to hiss
Tā shēn xīle yī kǒu qì, ránhòu mànmàn de xūle yī shēng.
他深吸了一口气，然后慢慢地嘘了一声。
He took a deep breath and then slowly exhaled.
Zài túshūguǎn lǐ, qǐng bùyào fāchū xū shēng.
在图书馆里，请不要发出嘘声。
In the library, please do not make hissing sounds.
Interjection
hush!
Tā yāoqiú wǒmen bǎochí xūshēng, yīnwèi tāmen zài kāihuì.
他要求我们保持嘘声，因为他们在开会。
He asked us to stay hush because they were having a meeting.
