diff --git a/html/semantics/popups/popup-attribute-basic.tentative.html b/html/semantics/popups/popup-attribute-basic.tentative.html
index efcd3355ebe24a..e7c2c316881b33 100644
--- a/html/semantics/popups/popup-attribute-basic.tentative.html
+++ b/html/semantics/popups/popup-attribute-basic.tentative.html
@@ -11,7 +11,7 @@
   <div popup="">Pop up</div>
   <div popup=auto>Pop up</div>
   <div popup=hint>Pop up</div>
-  <div popup=async>Pop up</div>
+  <div popup=manual>Pop up</div>
 </div>
 
 <div id=nonpopups>
@@ -158,7 +158,7 @@
     assert_false(popUp.matches(':top-layer'));
     popUp.showPopUp();
     assert_true(popUp.matches(':top-layer'));
-    popUp.setAttribute('popup','async');
+    popUp.setAttribute('popup','manual');
     assert_false(popUp.matches(':top-layer'));
     popUp.showPopUp();
     assert_true(popUp.matches(':top-layer'));
@@ -175,7 +175,7 @@
     }
   }
 
-  ["auto","hint","async"].forEach(type => {
+  ["auto","hint","manual"].forEach(type => {
     test((t) => {
       const popUp = createPopUp(t);
       popUp.setAttribute('popup',type);
diff --git a/html/semantics/popups/popup-backdrop-appearance-ref.tentative.html b/html/semantics/popups/popup-backdrop-appearance-ref.tentative.html
index 0327f3886fbcee..283eed24d3d7b5 100644
--- a/html/semantics/popups/popup-backdrop-appearance-ref.tentative.html
+++ b/html/semantics/popups/popup-backdrop-appearance-ref.tentative.html
@@ -40,7 +40,7 @@
   if there are 3 stacked boxes, with the brightest green on top.</p>
 <div popup id=bottom>Bottom
   <div popup=hint id=middle>Middle
-    <div popup=async id=top>Top</div>
+    <div popup=manual id=top>Top</div>
   </div>
 </div>
 <div id="bottom-backdrop" class="backdrop"></div>
diff --git a/html/semantics/popups/popup-backdrop-appearance.tentative.html b/html/semantics/popups/popup-backdrop-appearance.tentative.html
index da975d95b659d8..62005db75be4ec 100644
--- a/html/semantics/popups/popup-backdrop-appearance.tentative.html
+++ b/html/semantics/popups/popup-backdrop-appearance.tentative.html
@@ -41,7 +41,7 @@
   if there are 3 stacked boxes, with the brightest green on top.</p>
 <div popup id=bottom>Bottom
   <div popup=hint id=middle>Middle
-    <div popup=async id=top>Top</div>
+    <div popup=manual id=top>Top</div>
   </div>
 </div>
 <script>
diff --git a/html/semantics/popups/popup-defaultopen.tentative.html b/html/semantics/popups/popup-defaultopen.tentative.html
index 2e29d9a4afc356..7a82214623461c 100644
--- a/html/semantics/popups/popup-defaultopen.tentative.html
+++ b/html/semantics/popups/popup-defaultopen.tentative.html
@@ -11,8 +11,8 @@
 <div popup=hint id=p2b defaultopen>This is a hint popup with defaultopen, which should NOT be open upon load</div>
 <div popup id=p3>Also not visible</div>
 
-<div popup=async id=p4 defaultopen>This is an async popup with defaultopen, which should be open upon load</div>
-<div popup=async id=p5 defaultopen>This is an async popup with defaultopen, which should be open upon load</div>
+<div popup=manual id=p4 defaultopen>This is a manual popup with defaultopen, which should be open upon load</div>
+<div popup=manual id=p5 defaultopen>This is a manual popup with defaultopen, which should be open upon load</div>
 
 <script>
   requestAnimationFrame(() => {
@@ -26,8 +26,8 @@
         assert_true(p2.defaultOpen,'defaultopen should be present/true, even if not opened');
 
         assert_false(p2b.matches(':top-layer'),'Only the first popup/hint with defaultopen should be open on load');
-        assert_true(p4.matches(':top-layer'),'defaultopen should open all async popups');
-        assert_true(p5.matches(':top-layer'),'defaultopen should open all async popups');
+        assert_true(p4.matches(':top-layer'),'defaultopen should open all manual popups');
+        assert_true(p5.matches(':top-layer'),'defaultopen should open all manual popups');
 
         assert_false(p3.matches(':top-layer'));
         p3.setAttribute('defaultopen','');
diff --git a/html/semantics/popups/popup-invoking-attribute.tentative.html b/html/semantics/popups/popup-invoking-attribute.tentative.html
index ba461f807ea15e..6b356c1563b77e 100644
--- a/html/semantics/popups/popup-invoking-attribute.tentative.html
+++ b/html/semantics/popups/popup-invoking-attribute.tentative.html
@@ -107,7 +107,7 @@
     supported: false,
   },
 ];
-["auto","hint","async"].forEach(type => {
+["auto","hint","manual"].forEach(type => {
   invokers.forEach(testcase => {
     let t_set = [1], s_set = [1], h_set = [1];
     if (testcase.supported) {
diff --git a/html/semantics/popups/popup-light-dismiss.tentative.html b/html/semantics/popups/popup-light-dismiss.tentative.html
index a443be606dfabd..fc900439f8319f 100644
--- a/html/semantics/popups/popup-light-dismiss.tentative.html
+++ b/html/semantics/popups/popup-light-dismiss.tentative.html
@@ -417,7 +417,7 @@
 
 <div popup id=p10>Popup</div>
 <div popup=hint id=p11>Hint</div>
-<div popup=async id=p12>Async</div>
+<div popup=manual id=p12>Manual</div>
 <style>
   #p10 {top:100px;}
   #p11 {top:200px;}
@@ -427,26 +427,26 @@
 promise_test(async () => {
   const popup = document.querySelector('#p10');
   const hint = document.querySelector('#p11');
-  const async = document.querySelector('#p12');
+  const manual = document.querySelector('#p12');
   // All three can be open at once, if shown in this order:
   popup.showPopUp();
   hint.showPopUp();
-  async.showPopUp();
+  manual.showPopUp();
   assert_true(popup.matches(':top-layer'));
   assert_true(hint.matches(':top-layer'));
-  assert_true(async.matches(':top-layer'));
+  assert_true(manual.matches(':top-layer'));
   // The hint was opened last, so clicking it shouldn't close anything:
   await clickOn(hint);
   assert_true(popup.matches(':top-layer'),'popup should stay open');
   assert_true(hint.matches(':top-layer'),'hint should stay open');
-  assert_true(async.matches(':top-layer'),'async does not light dismiss');
-  // Clicking outside should close the hint and popup, but not the async:
+  assert_true(manual.matches(':top-layer'),'manual does not light dismiss');
+  // Clicking outside should close the hint and popup, but not the manual:
   await clickOn(outside);
   assert_false(popup.matches(':top-layer'),'popup should close');
   assert_false(hint.matches(':top-layer'),'hint should close');
-  assert_true(async.matches(':top-layer'),'async does not light dismiss');
-  async.hidePopUp();
-  assert_false(async.matches(':top-layer'));
+  assert_true(manual.matches(':top-layer'),'manual does not light dismiss');
+  manual.hidePopUp();
+  assert_false(manual.matches(':top-layer'));
   popup.showPopUp();
   hint.showPopUp();
   assert_true(popup.matches(':top-layer'));
diff --git a/html/semantics/popups/popup-types.tentative.html b/html/semantics/popups/popup-types.tentative.html
index 7334e3944b04cf..2b82fcd7542d57 100644
--- a/html/semantics/popups/popup-types.tentative.html
+++ b/html/semantics/popups/popup-types.tentative.html
@@ -7,15 +7,15 @@
 
 <div id=popup popup>Popup</div>
 <div id=hint popup=hint>Hint</div>
-<div id=async popup=async>Async</div>
-<div id=async2 popup=async>Async</div>
+<div id=manual popup=manual>Async</div>
+<div id=manual2 popup=manual>Async</div>
 
 <script>
-function assert_state_1(popupOpen,hintOpen,asyncOpen,async2Open) {
+function assert_state_1(popupOpen,hintOpen,manualOpen,manual2Open) {
   assert_equals(popup.matches(':top-layer'),popupOpen,'popup open state is incorrect');
   assert_equals(hint.matches(':top-layer'),hintOpen,'hint open state is incorrect');
-  assert_equals(async.matches(':top-layer'),asyncOpen,'async open state is incorrect');
-  assert_equals(async2.matches(':top-layer'),async2Open,'async2 open state is incorrect');
+  assert_equals(manual.matches(':top-layer'),manualOpen,'manual open state is incorrect');
+  assert_equals(manual2.matches(':top-layer'),manual2Open,'manual2 open state is incorrect');
 }
 test(() => {
   assert_state_1(false,false,false,false);
@@ -23,9 +23,9 @@
   assert_state_1(true,false,false,false);
   hint.showPopUp();
   assert_state_1(true,true,false,false);
-  async.showPopUp();
+  manual.showPopUp();
   assert_state_1(true,true,true,false);
-  async2.showPopUp();
+  manual2.showPopUp();
   assert_state_1(true,true,true,true);
   hint.hidePopUp();
   assert_state_1(true,false,true,true);
@@ -36,26 +36,26 @@
   assert_state_1(true,true,true,true);
   popup.hidePopUp();
   assert_state_1(false,false,true,true);
-  async.hidePopUp();
+  manual.hidePopUp();
   assert_state_1(false,false,false,true);
-  async2.hidePopUp();
+  manual2.hidePopUp();
   assert_state_1(false,false,false,false);
-},'hints and asyncs do not close popups');
+},'hints and manuals do not close popups');
 
 test(() => {
   assert_state_1(false,false,false,false);
   hint.showPopUp();
-  async.showPopUp();
-  async2.showPopUp();
+  manual.showPopUp();
+  manual2.showPopUp();
   assert_state_1(false,true,true,true);
   popup.showPopUp();
   assert_state_1(true,false,true,true);
   popup.hidePopUp();
   assert_state_1(false,false,true,true);
-  async.hidePopUp();
-  async2.hidePopUp();
+  manual.hidePopUp();
+  manual2.hidePopUp();
   assert_state_1(false,false,false,false);
-},'popups close hints but not asyncs');
+},'popups close hints but not manuals');
 </script>
 
 <div id=popup1 popup>Popup 1