肚脐在英文中叫作 navel 或者 belly button。它的来源是指在胎儿胎内受到营养的方式，就像植物通过茎和叶子接受营养一样。在出生后，肚脐是通过母亲的臍带将营养传递给胎儿的，所以它在出生后保留了下来。

一些英文例句：

She gently touched her baby's soft navel.

The doctor examined the newborn's navel to make sure it was healing properly.

He was so ticklish that she couldn't even touch his navel without him bursting into laughter.