Keyword cannibalisation
Two or more of your own pages competing for the same query, splitting the relevance between them.
What it means for a site you run
Cannibalisation wastes the work you already did: the new page competes with the old one, and search engines must pick between your own pages. The fix is usually to consolidate or to point the new page at a different query — but you have to notice first.
How Blogotter relates
Before a keyword can take a slot it is compared with the titles of your live pages and your Search Console queries. Past the warning threshold it lands in a review; past the blocking threshold it cannot be scheduled until you decide between refreshing the existing page and keeping a new one.