Does a cross in Weblio represent an obsolete kanji?


After looking at [this
question](https://japanese.stackexchange.com/questions/90171/example-sentence-
with-%E9%85%8C%E3%82%80) I went
[weblio](https://www.weblio.jp/content/%E9%85%8C%E3%82%80) to look up the
meaning of 酌む. The heading for the entry looks like this:

> く・む【×汲む／酌む】

I'm wondering what the cross next to 汲む means. I've seen this in a few things
I've looked up on Weblio and never managed to figure it out.

My guess is that it means 汲む is obsolete and I should use 酌む instead, but I'm
not at all sure. Indeed, in the comment I just saw on the linked question from
@Chocolate, I'm now certain my theory is wrong.

I assume Weblio has a page explaining its symbols but my Japanese isn't good
enough to find it.

