Secondary keywords
Secondary keywords are the related phrases a page targets alongside its main keyword, like synonyms, subtopics and longer versions.
Secondary keywords are the related phrases a page aims to rank for alongside its main keyword. If a page targets "coffee grinder," its secondary keywords might be "burr grinder," "best grinder for espresso" and "how to clean a coffee grinder." They're the other ways people ask about the same subject, and the subtopics a full answer would cover.
They matter because one good page usually ranks for hundreds of phrases. Planning the secondary ones makes sure the page covers what people actually want to know.
How to find them
Search your main keyword and look at what ranks. The top pages will cover the same handful of subtopics, and the questions in Google's "People also ask" box show you more. Keyword tools list the other phrases the top pages rank for.
Then use them where they fit naturally: in a heading, in a paragraph that answers that part of the question, in the alt text of a photo. A secondary keyword that needs to be forced in probably belongs on another page.
For example, Kestrel Roasters writes a page on French press coffee. Its main keyword is "French press coffee." Secondary keywords like "French press ratio," "coarse grind" and "how long to steep" each get a short section, so the page answers the questions that come next.
Why they help in AI search
When an AI platform answers a question, it often runs several related searches and reads the pages that come up. A page that covers the subtopics turns up in more of those searches, and it has a clear passage for each one, which makes it easier to quote. Covering the next question is worth more than repeating the main phrase.
In AnswerOrbit
The Demand tab in Topics shows the related questions people ask the AI platforms about a word or phrase. They're a good source of secondary keywords for a page, and you can click Track to follow any of them as a prompt. See Topics and prompts.