diff --git a/autotests/syntaxrepository_test.cpp b/autotests/syntaxrepository_test.cpp
--- a/autotests/syntaxrepository_test.cpp
+++ b/autotests/syntaxrepository_test.cpp
@@ -550,6 +550,28 @@
         QCOMPARE(klist.size(), 1);
         QVERIFY(klist.contains(QLatin1String("f")));
     }
+
+    void testKeywordListModification()
+    {
+        auto def = m_repo.definitionForName(QLatin1String("Python"));
+        QVERIFY(def.isValid());
+
+        const QStringList& lists = def.keywordLists();
+        QVERIFY(!lists.isEmpty());
+
+        const QString& listName = lists.first();
+        const QStringList keywords = def.keywordList(listName);
+
+        QStringList modified = keywords;
+        modified.append(QLatin1String("test"));
+
+        QVERIFY(def.setKeywordList(listName, modified) == true);
+        QCOMPARE(keywords + QStringList(QLatin1String("test")), def.keywordList(listName));
+
+        const QString& unexistedName = QLatin1String("unexisted-keyword-name");
+        QVERIFY(lists.contains(unexistedName) == false);
+        QVERIFY(def.setKeywordList(unexistedName, QStringList()) == false);
+    }
 };
 }
 
diff --git a/src/lib/definition.h b/src/lib/definition.h
--- a/src/lib/definition.h
+++ b/src/lib/definition.h
@@ -333,6 +333,21 @@
      */
     QStringList keywordList(const QString& name) const;
 
+    /**
+     * Set content of keyword list with name @p name to @p content
+     * Only existing keywordLists() can be changed. For non-existent keyword lists, false is returned.
+     * @see keywordList(), keywordLists()
+     *
+     * This function can be usefull for dynamic higlighting, when the document rehiglights more, that one time.
+     * For example, you have a program for editing and running Octave scripts files and
+     * you are using KSyntaxHighlighting for syntax higlighting. But also, you can request list of
+     * variables, functions, etc from corresponed Octave process.
+     * And, used this function, you can provide Octave live higlighting - by passing, for
+     * example, variables names from Octave to KSyntaxHighlighting variable keyword list via this function.
+     * @since 5.62
+     */
+    bool setKeywordList(const QString& name, const QStringList& content);
+
     /**
      * Returns a list of all Format items used by this definition.
      * The order of the Format items equals the order of the itemDatas in the xml file.
diff --git a/src/lib/definition.cpp b/src/lib/definition.cpp
--- a/src/lib/definition.cpp
+++ b/src/lib/definition.cpp
@@ -234,6 +234,19 @@
     return list ? list->keywords() : QStringList();
 }
 
+bool Definition::setKeywordList(const QString& name, const QStringList& content)
+{
+    d->load(DefinitionData::OnlyKeywords(true));
+    KeywordList* list = d->keywordList(name);
+    if (list)
+    {
+        list->setKeywordList(content);
+        return true;
+    }
+    else
+        return false;
+}
+
 QVector<Format> Definition::formats() const
 {
     d->load();
diff --git a/src/lib/keywordlist_p.h b/src/lib/keywordlist_p.h
--- a/src/lib/keywordlist_p.h
+++ b/src/lib/keywordlist_p.h
@@ -27,6 +27,7 @@
 #include <QSet>
 #include <QString>
 #include <QVector>
+#include <QStringList>
 
 #include <vector>
 
@@ -60,6 +61,14 @@
         return m_keywords;
     }
 
+    void setKeywordList(const QStringList& keywords)
+    {
+        m_keywords = keywords;
+        m_keywordsSortedCaseSensitive.clear();
+        m_keywordsSortedCaseInsensitive.clear();
+        initLookupForCaseSensitivity(m_caseSensitive);
+    }
+
     /** Checks if @p str is a keyword in this list. */
     bool contains(const QStringRef &str) const
     {