Keyword stuffing
Filling a page with the same words over and over to rank for them, which search engines treat as spam.
Keyword stuffing is filling a page with the words you want to rank for, over and over, until the text reads badly. It used to work on early search engines. Today Google lists it as spam in its spam policies, and a page that does it can rank lower or drop out of results.
What it looks like
For example, a page that says: "Looking for the best coffee subscription UK? Our coffee subscription UK is the best coffee subscription in the UK, so if you want a coffee subscription UK, choose our coffee subscription." Lists of city names a business doesn't really serve, and blocks of keywords hidden in the page's footer, are other forms of it.
Does it work in AI answers?
There's no reason to think so. An answer engine reads a page to find something that answers the question, and repeating a phrase doesn't add an answer. A page stuffed with a question's words, but with no clear answer to it, gives the platform nothing to quote.
What to do instead
Use the words your customers use, once, where they belong. When people ask which coffee subscription is cheapest in the UK, a page that has that question as a heading, and answers it in the first sentence underneath, is easier for both people and machines to use than a page that repeats the words cheap coffee subscription twenty times.
In AnswerOrbit
Two of the eight Page checks in Recommendations look at this. The prompt in a heading checks that a heading says what the prompt asks. An opening that answers checks that the page's opening paragraph speaks to it. Both reward saying it once, clearly. See Recommendations.