Correct

封口

/ fēngkǒu / 
Strokes

Definition

to close up/to heal (of wound)/to keep one's lips sealed

Example

As a Verb

seal sb's mouth; seal (off)

1
Yòng
用
jiāodài
胶带
bǎ
把
tā
他
de
的
kǒu
口
fēng
封
shàng
上

seal his mouth with tape

2
Méiyǒu
没有
fēngkǒu
封口
de
的
xìn
信

unsealed letter

As a Verb

close up; heal

3
Tā
他
bì
臂
shàng
上
de
的
shāng
伤
yǐjīng
已经
fēngkǒu
封口
le
了
  
。

The cut in his arm has closed up.

As a Verb

close a matter/an issue, leaving no room for further discussion

4
Tā
他
méi
没
fēngkǒu
封口
  
,
hái
还
kěyǐ
可以
shāngliang
商量
  
。

He hasn't closed the issue/matter. It is still open to discussion.

As a Verb

buy silence