Synonyms: Building a Real Coverage Strategy | Scouty

Most ecommerce stores manage synonyms the way they manage email folders: every few weeks, someone adds a new one and nobody ever cleans up. Eventually the list becomes unreadable, ineffective, or actively harmful.

This guide describes how to manage synonyms as a system, not a junk drawer.

The four kinds of synonyms

Every synonym rule belongs to one of four buckets. Naming them helps you reason about coverage.

1. Marketing-vs-internal

The shopper says one thing; the catalog says another.

• “couch” → “sofa”
• “trainers” → “sneakers”
• “hydrating” → “moisturizing”

These are usually one-way (rewrite shopper term to catalog term).

2. Brand-and-model

Brand and model variations.

• “iPhone” ↔ “Apple iPhone”
• “BMW E92” ↔ “BMW 3-Series Coupe E92”
• “Roomba i7” ↔ “iRobot Roomba i7”

These are usually two-way and need careful brand boundary handling.

3. Use-case

Shoppers describe what they want, not what it is.

• “for sensitive skin” → ingredients matching that intent
• “for muddy trails” → boots with high-grip outsoles
• “for sweaty feet” → moisture-wicking socks

These are hard to fix with synonyms alone. This is where semantic search starts to outperform rule-based work.

4. Tokenization

Same string, different separators.

• “BMW-E92” ↔ “BMW E92” ↔ “BMWE92”
• “USB-C” ↔ “USB C” ↔ “USBC”
• “5’10”” ↔ “5’10"" ↔ “5 ft 10”

These should usually be handled at the engine level, not as synonyms.

What “coverage” actually means

Coverage is the percentage of high-volume shopper queries handled correctly. It is not the size of your synonym list.

A 200-rule synonym list with bad coverage is worse than a 30-rule list with good coverage, because the bad list is harder to audit and more likely to have collateral damage.

Two questions to ask:

1. What percentage of your top 100 zero-result queries would be solved by a synonym?
2. What percentage of your top 100 high-volume queries currently hit a synonym rule?

If those numbers are low, you have a coverage problem.

Building a coverage map

A coverage map is a small document. A spreadsheet, a Notion page. That lists:

• The category or product line.
• The shopper’s preferred terminology.
• The catalog’s actual terminology.
• The synonym rule (if any) bridging the two.

Built once, it becomes a working document for merchandisers. Rebuilt quarterly, it stays useful.

Pruning bad rules

Old synonym lists collect bad rules. Two patterns to look for:

• Rules that fire too broadly. “Gel” mapped to a hair product but also matching knee braces.
• Rules that fire too narrowly. A synonym only relevant to a discontinued product.

Prune both. The list should shrink occasionally, not just grow.

Measuring synonym impact

Per rule, you should be able to answer:

• How many sessions hit this rule in the last 30 days?
• Of those, how many produced a click? A cart? A sale?

Rules that fire often but don’t produce conversions are usually not great rules. Rules that fire rarely but produce strong conversions are perfect, narrow ones.

Where synonyms stop working

Synonyms are great until they aren’t. The clear signal that you need more than rule-based work:

• Your zero-result list is dominated by use-case queries, not vocabulary mismatches.
• Adding new rules no longer reduces zero-result rate.
• Merchandisers spend more time auditing rules than running campaigns.

That is when semantic search earns its place. The vector index handles the long tail of phrasings that no synonym list will ever catch.

A simple synonym workflow

1. Triage zero-results weekly. Identify which buckets dominate.
2. Add synonyms for marketing-vs-internal and brand-and-model gaps.
3. For use-case gaps, layer in semantic search instead of more rules.
4. Audit the synonym list quarterly. Prune dead rules.
5. Measure rule impact. Keep what works.

How Scouty fits

Scouty surfaces zero-result queries, suggests synonyms grounded in your real catalog, lets you apply them with one click, and tracks impact per rule. For use-case queries that synonyms can’t catch, the semantic search add-on handles the long tail.

If you want a manual review of your existing synonym list and overall coverage, request a free expert-led Search Audit.