“盖儿”就是盖在东西上面的东西，比如瓶子上面的小盖儿。

"盖儿" refers to something that covers another object, like the small cover on a bottle.

这是北方口语里常说的词，意思和“盖子”一样。

This is a common term in northern spoken Chinese, meaning the same as "盖子" (lid).