SEO course › Part 2: Keyword research
Semantic keywords are words and phrases closely related in meaning to your main keyword, such as synonyms, subtopics and connected concepts. They help search engines and readers understand what your page is really about. Using them naturally lets you cover a topic fully, instead of repeating one exact phrase again and again.
This lesson explains what semantic keywords are, how search engines understand meaning and entities, and how to use related terms to build topical relevance.
What are semantic keywords?
“Semantic” means related to meaning. Semantic keywords are terms that belong to the same topic as your main keyword.
Take a page about “how to make filter coffee”. Related terms include decoction, coffee filter, chicory, dabara set, South Indian coffee and milk ratio. A complete guide would naturally mention most of these.
Semantic keywords are not only synonyms. They include the parts, steps, tools, questions and ideas that a knowledgeable person would expect to find on the topic.
You may see the term “LSI keywords” online. It refers to latent semantic indexing, an older information retrieval method. Google has said it does not use LSI keywords, so it is better to think simply in terms of related terms and full topic coverage.
How do search engines understand meaning?
In the early days, search engines relied heavily on matching exact words. That made it easy to rank pages by repeating a keyword, a practice called keyword stuffing.
Over time, Google has gotten much better at understanding language. Some well-known milestones:
- Hummingbird (2013) helped Google understand the meaning of whole queries, not just single words.
- RankBrain (2015) helped Google handle searches it had not seen before.
- BERT (2019) improved understanding of how words relate to each other in a sentence.
Because of this, Google can often recognize that “cheap flights to Goa” and “low cost Goa air tickets” mean the same thing. You no longer need an exact-match phrase in every heading. The Google algorithm updates lesson covers these changes in more detail.
What are entities in SEO?
An entity is a specific, distinct thing, such as a person, place, organization, product or concept. “Charminar”, “Hyderabad”, “biryani” and “the Reserve Bank of India” are all entities.
Google has said it uses a Knowledge Graph, a large database of entities and the relationships between them. This helps it understand that Charminar is a monument in Hyderabad, and that Hyderabadi biryani is a dish linked to that city.
When your page clearly mentions relevant entities, it becomes easier for search engines to understand the context. A page about “Hyderabadi dum biryani” that mentions basmati rice, saffron, dum cooking and the city itself sends a clear topical picture.
| Term | What it means | Example for a biryani page |
|---|---|---|
| Main keyword | The primary search term you target | hyderabadi dum biryani recipe |
| Semantic keywords | Related words and phrases on the same topic | marination, layering, dum cooking, raita |
| Entities | Specific named things search engines recognize | Hyderabad, basmati rice, saffron |
| Topical relevance | How well the page covers the whole topic | Ingredients, method, timings, serving tips |
How do semantic keywords build topical relevance?
Topical relevance is how clearly and completely a page covers its subject. A page with strong topical relevance answers the main question and the natural follow-up questions.
Semantic keywords are a sign of that coverage, not a trick to fake it. If you write a genuinely useful guide, most related terms appear on their own. Checking for missing terms helps you spot subtopics you forgot.
This also matters for AI search. AI Overviews and chat-style answers try to summarize a topic, and pages that explain concepts clearly and completely are easier to understand and cite. Our posts on generative engine optimization and answer engine optimization explore this further.
Over a whole site, covering related subtopics across several linked pages builds broader topical authority, which is covered in its own lesson on topical authority.
How do you find semantic keywords?
You can find related terms with free methods.
- Search your main keyword and read the top-ranking pages. Note the subtopics and terms they share.
- Check People Also Ask boxes and related searches at the bottom of the results. The keyword ideas from Google lesson shows how.
- Look at Google Autocomplete suggestions as you type your keyword.
- Review your own Search Console queries for related terms your page already appears for.
- Ask customers or read reviews to learn the words real people use.
- List the entities involved: places, products, tools, ingredients or people linked to the topic.
Example: semantic keywords for a Pune yoga studio
A small yoga studio in Pune wants its “yoga for back pain” page to rank. The first draft repeats “yoga for back pain” many times but says little else.
After researching related terms, the owner adds sections on specific poses such as cat-cow and child’s pose, posture tips for desk workers, breathing, and when to see a doctor first. Terms like lower back, stiffness, flexibility and physiotherapist now appear naturally.
The page is now more helpful, and it clearly signals the full topic without stuffing the main phrase.
Common mistakes to avoid
- Stuffing lists of related terms into a page without using them in meaningful sentences.
- Chasing “LSI keyword” tools as if they reveal a Google ranking factor.
- Adding off-topic entities just to look comprehensive.
- Ignoring the words your real customers use in favor of tool suggestions.
Key takeaways
- Semantic keywords are related terms, subtopics and concepts that belong to the same topic.
- Google understands meaning and entities, so exact-match repetition is no longer needed.
- Entities are specific named things; mentioning relevant ones adds clear context.
- Full, natural topic coverage builds topical relevance and helps with AI search too.
- Find related terms from search results, People Also Ask, autocomplete, Search Console and customers.
Frequently asked questions
Are semantic keywords the same as LSI keywords?
Not really. LSI is an old indexing method that Google has said it does not use, while semantic keywords simply means related terms that help cover a topic.
How many semantic keywords should a page include?
There is no set number. Cover the topic well for the reader, and the right related terms will usually appear naturally.
Do semantic keywords help with featured snippets?
They can help indirectly. Clear, complete answers that use natural language make it easier for Google to pick your content for SERP features, but nothing guarantees a snippet.
Previous lesson: Keyword cannibalization: how to identify and fix it
Next lesson: Topic clusters: how to plan pillar pages and supporting content