MetaExtension language
This tag is used to declare the language of the website.
It is not necessary and should generally not be used. Use <html lang="en"> instead, to declare your websites language.
Search enginges like Google automatically detect your default language.
Read more about it on Googles Developer Blog.
Usage
<meta name="language" content="en">Also refer to alternate(lang).
W3
In the WHATWG Wiki
Up to date: v2.3.5