封口的英文：
heal; seal

参考例句：

Impulse sealing
脉冲封口

Sealing packing machine
封口包装机

Cop Seal (Shrinkable Films)
热收缩封口套

The(flap of the)envelope was unstuck.
信封(的封口)没粘住.

The flap of the envelope was unstuck.
信封的封口没粘住。

The seal on the jar was broken.
瓶的封口被打开了。

Fasten(the cover,flap,etc of sth)with glue,paste,etc
(用胶水、浆糊等)粘住(封套、信封口等)

The flap of the envelope has come unstuck.
信封口的黏胶黏不住了。

During sealing, printing date, lot No. and mark which are available with clean and perfect looking.
封口同时印制生产日期及批号、商标,并保证清晰美观。

heal是什么意思：
v. 愈合，治愈；结束，较容易忍受；调停，消除

heal the breach
弥合裂痕,调停

A green wound is soon healed
新伤容易愈合

Time heals all sorrows.
时间可治愈一切悲伤。

The wound is healing fast.
伤口愈合得很快。

Time heals most pains.
时间会消除很多痛苦。

seal是什么意思：
n. 海豹；图案，印章；封印；保证，誓约；标志，象征
v. 保证；密封；确定；盖章；密封

A stamp or seal meant to be impressed.
图章用来盖戳的图章或印章

The experience seals their friendship.
这一经历确定了他们的友谊。

Sealing is prohibited in many countries.
许多国家禁止捕海豹。

The probe unit is hermetically sealed.
探头装置是密封的。

It was stored in a tube with a break seal.
它保存在一个有断裂密封垫的试管里。