Correct

语塞

/ yǔsè / 
Strokes

Definition

to be at a loss for words/speechless

Example

As a Verb

[due to excitement, anger, shame etc] be unable to utter a word; be tongue-tied; be speechless

1
Zhège
这个
wèntí
问题
líng
令
tā
他
wánquán
完全
mángrán
茫然
yǔsè
语塞
  
。

This question left him at a complete loss for words.

2
Cí
词
qíong
穷
yǔ
语
sè
塞

be rendered speechless for want of words