Good question, the general guidance in this case is to not edit the post. Looking at the answer below it's different; you stumbled upon a suggested edit adding spam and inadvertently approved/improved it – the right course of action is to reject it as spam/vandalism, and only then edit it.
This issue (whether to edit spam or not) comes up frequently ...
Here’s my side of things:
I saw the question (before any major edits) and wanted to quote some of the Wikipedia article for context.
I tried to do that but stopped when it looked like the edit would have answered the question, by having a link to a page with a definition of the term.
It was at that point that I voted to close the question, the fourth close ...
If we assume this is what the OP meant,
That is what should have been done. Despite the poor syntax, we have
Can someone tell me where this word comes from?
I can’t see that there is much that is unclear about that.
It is not a matter of whether or not the OP comes back – EL&U is creating a reference source, so, for what it’s worth:
The word starts in ...
Regarding your update:
This particular item of spam was not part of the original post. It was a suggested edit.
The spam wasn't posted by the question asker, so if I had flagged the post as spam it would have put a black mark against the wrong person.
This is why I edited out the link.
I'm glad you didn't edit out the link and flagged it, because that ...