Why your search engine can't read minds (and what to do about it)

Your customers don't search the way you write. They use slang, acronyms, brand names, dialect and plain English where you've used technical terms. If your search engine only matches exact words, it's failing people silently, returning nothing, or returning the wrong thing, and most of the time nobody tells you.

Synonyms are the fix. They're one of the most powerful tools in search configuration, and one of the most consistently underused.

A synonym tells your search engine that two terms are related. When someone searches for one, the engine returns results for the other as well. It sounds simple because it is. But the impact on findability can be significant, particularly for sites where the gap between expert language and everyday language is wide.

There are five types of synonym worth knowing about.

These are the thesaurus-style equivalents: two words that mean the same thing, just in different registers.

A clinical site might map "hyper" to "elevated" or "high." A legal site might map "intestate" to "dying without a will." A financial site might map "equity release" to "lifetime mortgage."

Pure synonyms are also where acronyms live. If your content uses "NHS" but some users search for "National Health Service," or vice versa, a synonym resolves the mismatch without requiring you to stuff every page with both forms.

These handle the cases where someone is searching for something you don't stock, but you do stock the equivalent.

The classic example is competing brands: if you only sell Coca-Cola and someone searches for Pepsi, a translation synonym can surface your results rather than a dead end. The same logic applies to discontinued product names, older model numbers, or rebrand situations where customers still use the old name.

This type of synonym requires care. You're making an editorial decision about equivalence, and that decision needs to be accurate and honest.

Language varies by region, and search engines don't always bridge that gap automatically.

Most engines will handle spelling variants like "colour" and "color" at the character level. What they won't do is translate concepts between dialects. "High school" and "secondary school" mean the same educational stage but come from different sides of the Atlantic. If your content uses one term and your audience reaches for the other, a localisation synonym closes the gap.

This is particularly relevant for any organisation serving a geographically or culturally mixed audience.

Colloquialisms are the words people use in real life rather than in formal writing. They vary by region, by age group and by context, and they're often the first thing someone types into a search box.

"Bum," "bottom" and "backside" are the same body part. "Trainers," "sneakers" and "gym shoes" are the same footwear. If your product descriptions use one term and your customers use another, you're creating friction that synonyms can eliminate.

Colloquial synonyms are also an accessibility tool. Plain, familiar language is easier to process for people with cognitive disabilities, low literacy, or English as a second language. Getting colloquialisms right is not just good search practice; it's good inclusion practice.

These are the most complex type and the most powerful when done well. Instead of a simple one-to-one relationship, linking synonyms create a chain of associations.

Take a pharmacy or NHS information site. Someone might search for "Nurofen" (a brand name), "ibuprofen" (the generic drug name), or "NSAIDs" (the drug category). A well-constructed set of linking synonyms connects all three:

Someone searching at any point in that chain reaches relevant content. They don't need to know the clinical term to find clinical information.

Linking synonyms need thought and testing. Get the chain wrong and you create misleading associations. Get it right and you've significantly improved the reach and relevance of your search results.

If you've never configured synonyms before, start with the evidence. Look at your search logs for queries that return no results or low-engagement results. Those failed searches are a direct record of the language your users reach for and the gaps your current configuration doesn't cover.

That list is your synonym backlog. Work through it by type, test as you go, and review it regularly. Language changes, your catalogue changes, and your synonym configuration needs to keep pace.

Done well, synonyms are invisible. Your users just find what they're looking for. That's exactly how it should work.

Murmuration helps retailers and digital teams understand and fix onsite search. Get in touch if you'd like to talk through what a diagnostic might look like for your site.