diff --git a/doc_test.go b/doc_test.go
index ffc8da9..3a4ebd1 100644
--- a/doc_test.go
+++ b/doc_test.go
@@ -179,7 +179,11 @@ func (s *stubField) Compose(field string, length int, freq index.TokenFrequencie
 
 // -----------------------------------------------------------------------------
 type stubSynonymField struct {
-	name       string
+	name     string
+	analyzer string
+	input    []string
+	synonyms []string
+
 	synonymMap map[string][]string
 }
 
@@ -200,7 +204,18 @@ func (s *stubSynonymField) EncodedFieldType() byte {
 }
 
 func (s *stubSynonymField) Analyze() {
-
+	var analyzedInput []string
+	if len(s.input) > 0 {
+		analyzedInput = make([]string, 0, len(s.input))
+		for _, term := range s.input {
+			analyzedInput = append(analyzedInput, analyzeStubTerm(term, s.analyzer))
+		}
+	}
+	analyzedSynonyms := make([]string, 0, len(s.synonyms))
+	for _, syn := range s.synonyms {
+		analyzedSynonyms = append(analyzedSynonyms, analyzeStubTerm(syn, s.analyzer))
+	}
+	s.synonymMap = processSynonymData(analyzedInput, analyzedSynonyms)
 }
 
 func (s *stubSynonymField) Options() index.FieldIndexingOptions {
@@ -219,30 +234,46 @@ func (s *stubSynonymField) NumPlainTextBytes() uint64 {
 	return 0
 }
 
-func (sf *stubSynonymField) VisitSynonymDefinitions(visitor func(term string, synonyms []string)) {
+func (sf *stubSynonymField) IterateSynonyms(visitor func(term string, synonyms []string)) {
 	for term, synonyms := range sf.synonymMap {
 		visitor(term, synonyms)
 	}
 }
 
-func analyzeStubTerm(term string) string {
+func processSynonymData(input []string, synonyms []string) map[string][]string {
+	var synonymMap map[string][]string
+	if len(input) > 0 {
+		// Map each term to the same list of synonyms.
+		synonymMap = make(map[string][]string, len(input))
+		for _, term := range input {
+			synonymMap[term] = append([]string(nil), synonyms...) // Avoid sharing slices.
+		}
+	} else {
+		synonymMap = make(map[string][]string, len(synonyms))
+		// Precompute a map where each synonym points to all other synonyms.
+		for i, elem := range synonyms {
+			synonymMap[elem] = make([]string, 0, len(synonyms)-1)
+			for j, otherElem := range synonyms {
+				if i != j {
+					synonymMap[elem] = append(synonymMap[elem], otherElem)
+				}
+			}
+		}
+	}
+	return synonymMap
+}
+
+func analyzeStubTerm(term string, analyzer string) string {
 	lowerCaseTerm := strings.ToLower(term)
 	return lowerCaseTerm
 }
 
-func newStubSynonymField(name, analyzer string, synonymMap map[string][]string) index.SynonymField {
-	analyzedSynonymDefs := make(map[string][]string, len(synonymMap))
-	for term, synonyms := range synonymMap {
-		analyzedTerm := analyzeStubTerm(term)
-		analyzedSynonyms := make([]string, 0, len(synonyms))
-		for _, syn := range synonyms {
-			analyzedSynonyms = append(analyzedSynonyms, analyzeStubTerm(syn))
-		}
-		analyzedSynonymDefs[analyzedTerm] = analyzedSynonyms
-	}
+func newStubSynonymField(name string, analyzer string, input []string, synonyms []string) index.SynonymField {
 	return &stubSynonymField{
-		name:       name,
-		synonymMap: analyzedSynonymDefs,
+		name:     name,
+		analyzer: analyzer,
+		input:    input,
+		synonyms: synonyms,
 	}
 }
 
diff --git a/section_synonym.go b/section_synonym.go
index 6828028..ef237bc 100644
--- a/section_synonym.go
+++ b/section_synonym.go
@@ -143,7 +143,7 @@ func (so *synonymIndexOpaque) process(field index.SynonymField, fieldID uint16,
 
 	termSynMap := so.SynonymTermToID[tid]
 
-	field.VisitSynonymDefinitions(func(term string, synonyms []string) {
+	field.IterateSynonyms(func(term string, synonyms []string) {
 		pid := thesaurus[term] - 1
 
 		bs := so.Synonyms[pid]
@@ -183,7 +183,7 @@ func (so *synonymIndexOpaque) realloc() {
 
 				termSynMap := so.SynonymTermToID[thesaurusID]
 
-				synField.VisitSynonymDefinitions(func(term string, synonyms []string) {
+				synField.IterateSynonyms(func(term string, synonyms []string) {
 					_, exists := thesaurus[term]
 					if !exists {
 						pidNext++
diff --git a/thesaurus_test.go b/thesaurus_test.go
index a545c2f..f4e6b99 100644
--- a/thesaurus_test.go
+++ b/thesaurus_test.go
@@ -27,33 +27,15 @@ import (
 	segment "github.com/blevesearch/scorch_segment_api/v2"
 )
 
-func createEquivalentSynonymMap(input []string, resultMap map[string][]string) map[string][]string {
-	if resultMap == nil {
-		resultMap = make(map[string][]string)
-	}
-	for _, elem := range input {
-		for _, otherElem := range input {
-			if elem != otherElem {
-				resultMap[elem] = append(resultMap[elem], otherElem)
-			}
-		}
-	}
-	return resultMap
-}
-
-func buildTestSynonymDocument(id string, collection string, terms []string, synonyms []string) index.Document {
-	var synonymMap map[string][]string
-	if terms == nil {
-		numEntries := len(synonyms) * (len(synonyms) - 1)
-		synonymMap = make(map[string][]string, numEntries)
-		synonymMap = createEquivalentSynonymMap(synonyms, synonymMap)
-	} else {
-		synonymMap = make(map[string][]string, len(terms))
-		for _, term := range terms {
-			synonymMap[term] = synonyms
-		}
-	}
-	synDoc := newStubSynonymDocument(id, newStubSynonymField(collection, "standard", synonymMap))
+func buildTestSynonymDocument(id string, synonymSource string, terms []string, synonyms []string) index.Document {
+	// Create the synonym document using stubs.
+	stubAnalyzer := "standard"
+	// Create the synonym field.
+	synField := newStubSynonymField(synonymSource, stubAnalyzer, terms, synonyms)
+	// Analyze the synonyms.
+	synField.Analyze()
+	// Create the synonym document.
+	synDoc := newStubSynonymDocument(id, synField)
 	synDoc.AddIDField()
 	return synDoc
 }
@@ -122,7 +104,7 @@ func checkWithDeletes(except *roaring.Bitmap, collectionName string, testSynonym
 		if len(synonyms) != len(expectedSynonyms) {
 			return errors.New("unexpected number of synonyms, expected: " +
 				strconv.Itoa(len(expectedSynonyms)) + " got: " +
-				strconv.Itoa(len(synonyms)) + " for term: " + term + " when excepting: " + except.String())
+				strconv.Itoa(len(synonyms)) + " for term: " + term)
 		}
 		sort.Strings(synonyms)
 		sort.Strings(expectedSynonyms)
@@ -167,6 +149,20 @@ type testSynonymDefinition struct {
 	synonyms       []string
 }
 
+func createEquivalentSynonymMap(input []string, resultMap map[string][]string) map[string][]string {
+	if resultMap == nil {
+		resultMap = make(map[string][]string)
+	}
+	for _, elem := range input {
+		for _, otherElem := range input {
+			if elem != otherElem {
+				resultMap[elem] = append(resultMap[elem], otherElem)
+			}
+		}
+	}
+	return resultMap
+}
+
 func createExpectedSynonymMap(input []testSynonymDefinition) map[string][]string {
 	rv := make(map[string][]string)
 	for _, testSynonymDefinition := range input {