diff --git a/core/core.libraries.yml b/core/core.libraries.yml
index 0b3b12855f..ecaea2907f 100644
--- a/core/core.libraries.yml
+++ b/core/core.libraries.yml
@@ -122,7 +122,7 @@ drupal.checkbox:
 drupal.collapse:
   version: VERSION
   js:
-    misc/details-content-synopsis.js: {}
+    misc/details-summary-outline.js: {}
     misc/details-aria.js: {}
     misc/collapse.js: {}
   dependencies:
diff --git a/core/misc/details-content-synopsis.es6.js b/core/misc/details-summary-outline.es6.js
similarity index 50%
rename from core/misc/details-content-synopsis.es6.js
rename to core/misc/details-summary-outline.es6.js
index b724a279e0..442fdf42ce 100644
--- a/core/misc/details-content-synopsis.es6.js
+++ b/core/misc/details-summary-outline.es6.js
@@ -1,37 +1,37 @@
 /**
  * @file
- * Adds a synopsis of a details element's contents to its summary.
+ * Adds an outline of a details element's contents to its summary.
  */
 (($, Drupal) => {
   /**
-   * The DetailsContentSynopsis object represents a single details element.
+   * The DetailsSummaryOutline object represents a single details element.
    *
-   * @constructor Drupal.DetailsContentSynopsis
+   * @constructor Drupal.DetailsSummaryOutline
    *
    * @param {HTMLElement} node
    *   A details element, the summary of which may have supplemental text.
-   *   The supplemental text is a synopsis of the details element's contents.
+   *   The supplemental text is summarizes the details element's contents.
    */
-  function DetailsContentSynopsis(node) {
+  function DetailsSummaryOutline(node) {
     this.$node = $(node);
     this.setupSummary();
   }
 
   $.extend(
-    DetailsContentSynopsis,
-    /** @lends Drupal.DetailsContentSynopsis */ {
+    DetailsSummaryOutline,
+    /** @lends Drupal.DetailsSummaryOutline */ {
       /**
-       * Holds references to instantiated DetailsContentSynopsis objects.
+       * Holds references to instantiated DetailsSummaryOutline objects.
        *
-       * @type {Array.<Drupal.DetailsContentSynopsis>}
+       * @type {Array.<Drupal.DetailsSummaryOutline>}
        */
       instances: [],
     },
   );
 
   $.extend(
-    DetailsContentSynopsis.prototype,
-    /** @lends Drupal.DetailsContentSynopsis# */ {
+    DetailsSummaryOutline.prototype,
+    /** @lends Drupal.DetailsSummaryOutline# */ {
       /**
        * Initialize and setup summary events and markup.
        *
@@ -40,14 +40,14 @@
        * @listens event:summaryUpdated
        */
       setupSummary() {
-        this.$synopsizedDetailsContentWrapper = $(
-          Drupal.theme('synopsizedDetailsContentWrapper'),
+        this.$detailsSummaryOutlineWrapper = $(
+          Drupal.theme('detailsSummaryOutlineWrapper'),
         );
         this.$node
           .on('summaryUpdated', $.proxy(this.onSummaryUpdated, this))
           .trigger('summaryUpdated')
           .find('> summary')
-          .append(this.$synopsizedDetailsContentWrapper);
+          .append(this.$detailsSummaryOutlineWrapper);
       },
 
       /**
@@ -55,15 +55,15 @@
        */
       onSummaryUpdated() {
         const text = $.trim(this.$node.drupalGetSummary());
-        this.$synopsizedDetailsContentWrapper.html(
-          Drupal.theme('synopsizedDetailsContent', text),
+        this.$detailsSummaryOutlineWrapper.html(
+          Drupal.theme('detailsSummaryOutlineContent', text),
         );
       },
     },
   );
 
   /**
-   * Adds a synopsis of a details element's contents to its summary.
+   * Adds an outline of a details element's contents to its summary.
    *
    * @type {Drupal~behavior}
    *
@@ -78,27 +78,28 @@
       $detailsElements.map(
         (index, details) =>
           // eslint-disable-next-line no-new
-          new DetailsContentSynopsis(details),
+          new DetailsSummaryOutline(details),
       );
     },
   };
 
   /**
-   * The element containing the synopsis of the detail element's contents.
+   * The element containing the outline of the detail element's contents.
    *
    * @return {string}
-   *   The markup for the element that will contain the synopsis text.
+   *   The markup for the element that will contain the outline text.
    */
-  Drupal.theme.synopsizedDetailsContentWrapper = () =>
+  Drupal.theme.detailsSummaryOutlineWrapper = () =>
     `<span class="summary"></span>`;
 
   /**
-   * Formats a summary's synopsis text.
+   * Formats a summary's outline text.
    *
    * @param {string|null} [text]
-   *   (optional) The synopsis text displayed by the summary.
+   *   (optional) The outline text displayed by the summary.
    * @return {string}
-   *   The formatted synopsis text.
+   *   The formatted outline text.
    */
-  Drupal.theme.synopsizedDetailsContent = text => (text ? ` (${text})` : '');
+  Drupal.theme.detailsSummaryOutlineContent = text =>
+    text ? ` (${text})` : '';
 })(jQuery, Drupal);
diff --git a/core/misc/details-content-synopsis.js b/core/misc/details-summary-outline.js
similarity index 61%
rename from core/misc/details-content-synopsis.js
rename to core/misc/details-summary-outline.js
index f3b60768c3..374f080292 100644
--- a/core/misc/details-content-synopsis.js
+++ b/core/misc/details-summary-outline.js
@@ -6,38 +6,38 @@
 **/
 
 (function ($, Drupal) {
-  function DetailsContentSynopsis(node) {
+  function DetailsSummaryOutline(node) {
     this.$node = $(node);
     this.setupSummary();
   }
 
-  $.extend(DetailsContentSynopsis, {
+  $.extend(DetailsSummaryOutline, {
     instances: []
   });
-  $.extend(DetailsContentSynopsis.prototype, {
+  $.extend(DetailsSummaryOutline.prototype, {
     setupSummary: function setupSummary() {
-      this.$synopsizedDetailsContentWrapper = $(Drupal.theme('synopsizedDetailsContentWrapper'));
-      this.$node.on('summaryUpdated', $.proxy(this.onSummaryUpdated, this)).trigger('summaryUpdated').find('> summary').append(this.$synopsizedDetailsContentWrapper);
+      this.$detailsSummaryOutlineWrapper = $(Drupal.theme('detailsSummaryOutlineWrapper'));
+      this.$node.on('summaryUpdated', $.proxy(this.onSummaryUpdated, this)).trigger('summaryUpdated').find('> summary').append(this.$detailsSummaryOutlineWrapper);
     },
     onSummaryUpdated: function onSummaryUpdated() {
       var text = $.trim(this.$node.drupalGetSummary());
-      this.$synopsizedDetailsContentWrapper.html(Drupal.theme('synopsizedDetailsContent', text));
+      this.$detailsSummaryOutlineWrapper.html(Drupal.theme('detailsSummaryOutlineContent', text));
     }
   });
   Drupal.behaviors.detailsSummary = {
     attach: function attach(context) {
       var $detailsElements = $(context).find('details').once('details');
       $detailsElements.map(function (index, details) {
-        return new DetailsContentSynopsis(details);
+        return new DetailsSummaryOutline(details);
       });
     }
   };
 
-  Drupal.theme.synopsizedDetailsContentWrapper = function () {
+  Drupal.theme.detailsSummaryOutlineWrapper = function () {
     return "<span class=\"summary\"></span>";
   };
 
-  Drupal.theme.synopsizedDetailsContent = function (text) {
+  Drupal.theme.detailsSummaryOutlineContent = function (text) {
     return text ? " (".concat(text, ")") : '';
   };
 })(jQuery, Drupal);
\ No newline at end of file
diff --git a/core/modules/node/tests/src/FunctionalJavascript/CollapsedSummariesTest.php b/core/modules/node/tests/src/FunctionalJavascript/CollapsedSummariesTest.php
index 1b1b743833..e6736c9ea6 100644
--- a/core/modules/node/tests/src/FunctionalJavascript/CollapsedSummariesTest.php
+++ b/core/modules/node/tests/src/FunctionalJavascript/CollapsedSummariesTest.php
@@ -5,7 +5,7 @@
 use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
 
 /**
- * Tests that summaries of form values are displayed on meta details elements.
+ * Tests that outlines of node meta values are displayed in summaries and tabs.
  *
  * @group node
  */
diff --git a/core/themes/claro/js/details.es6.js b/core/themes/claro/js/details.es6.js
index ff25f0453c..33a0708aca 100644
--- a/core/themes/claro/js/details.es6.js
+++ b/core/themes/claro/js/details.es6.js
@@ -57,21 +57,21 @@
   };
 
   /**
-   * Theme override of element containing supplemental summary text.
+   * Theme override providing a wrapper for a detail element's content outline.
    *
    * @return {string}
-   *   The markup for the element that will contain supplemental summary text.
+   *   The markup for the element that will contain the content outline.
    */
-  Drupal.theme.detailsSummarySummary = () =>
+  Drupal.theme.detailsSummaryOutlineWrapper = () =>
     `<span class="claro-details__summary-summary"></span>`;
 
   /**
-   * Theme override of supplemental summary text.
+   * Theme override of a summary's outline text.
    *
    * @param {string|null} [text]
-   *   (optional) The additional text displayed by the summary.
+   *   (optional) The outline text displayed by the summary.
    * @return {string}
-   *   The formatted text that will be appended to the summary element.
+   *   The formatted outline text.
    */
-  Drupal.theme.detailsSummarySummaryText = text => text || '';
+  Drupal.theme.detailsSummaryOutlineContent = text => text || '';
 })(jQuery, Modernizr, Drupal);
diff --git a/core/themes/claro/js/details.js b/core/themes/claro/js/details.js
index bb9462446c..ead19595ea 100644
--- a/core/themes/claro/js/details.js
+++ b/core/themes/claro/js/details.js
@@ -32,11 +32,11 @@
     }
   };
 
-  Drupal.theme.detailsSummarySummary = function () {
+  Drupal.theme.detailsSummaryOutlineWrapper = function () {
     return "<span class=\"claro-details__summary-summary\"></span>";
   };
 
-  Drupal.theme.detailsSummarySummaryText = function (text) {
+  Drupal.theme.detailsSummaryOutlineContent = function (text) {
     return text || '';
   };
 })(jQuery, Modernizr, Drupal);
\ No newline at end of file