diff --git a/core/src/main/java/org/opensearch/sql/planner/logical/LogicalPlanDSL.java b/core/src/main/java/org/opensearch/sql/planner/logical/LogicalPlanDSL.java
index f2dfdfe661..2ab7aeb533 100644
--- a/core/src/main/java/org/opensearch/sql/planner/logical/LogicalPlanDSL.java
+++ b/core/src/main/java/org/opensearch/sql/planner/logical/LogicalPlanDSL.java
@@ -143,8 +143,8 @@ public static LogicalPlan lookup(
       LogicalPlan input,
       String indexName,
       Map<ReferenceExpression, ReferenceExpression> matchFieldMap,
-      Boolean appendOnly,
+      Boolean overwrite,
       Map<ReferenceExpression, ReferenceExpression> copyFields) {
-    return new LogicalLookup(input, indexName, matchFieldMap, appendOnly, copyFields);
+    return new LogicalLookup(input, indexName, matchFieldMap, overwrite, copyFields);
   }
 }
diff --git a/core/src/main/java/org/opensearch/sql/planner/physical/PhysicalPlanDSL.java b/core/src/main/java/org/opensearch/sql/planner/physical/PhysicalPlanDSL.java
index acb7df9f0b..ed95cd8dbd 100644
--- a/core/src/main/java/org/opensearch/sql/planner/physical/PhysicalPlanDSL.java
+++ b/core/src/main/java/org/opensearch/sql/planner/physical/PhysicalPlanDSL.java
@@ -88,11 +88,11 @@ public static LookupOperator lookup(
       PhysicalPlan input,
       String indexName,
       Map<ReferenceExpression, ReferenceExpression> matchFieldMap,
-      Boolean appendOnly,
+      Boolean overwrite,
       Map<ReferenceExpression, ReferenceExpression> copyFieldMap,
       BiFunction<String, Map<String, Object>, Map<String, Object>> lookupFunction) {
     return new LookupOperator(
-        input, indexName, matchFieldMap, appendOnly, copyFieldMap, lookupFunction);
+        input, indexName, matchFieldMap, overwrite, copyFieldMap, lookupFunction);
   }
 
   public WindowOperator window(
diff --git a/docs/user/ppl/cmd/lookup.rst b/docs/user/ppl/cmd/lookup.rst
index 03cb089b5c..3e64fd46f1 100644
--- a/docs/user/ppl/cmd/lookup.rst
+++ b/docs/user/ppl/cmd/lookup.rst
@@ -15,12 +15,12 @@ Description
 
 Syntax
 ============
-lookup <lookup-index> <lookup-field> [AS <local-lookup-field>] ["," <lookup-field> [AS <local-lookup-field>]]... [appendonly=<bool>] [<source-field> [AS <local-source-field>]] ["," <source-field> [AS <local-source-field>]]...
+lookup <lookup-index> <lookup-field> [AS <local-lookup-field>] ["," <lookup-field> [AS <local-lookup-field>]]... [overwrite=<bool>] [<source-field> [AS <local-source-field>]] ["," <source-field> [AS <local-source-field>]]...
 
 * lookup-index: mandatory. the name of the lookup index. If more than one is provided, all of them must match.
 * lookup-field: mandatory. the name of the lookup field. Must be existing in the lookup-index. It is used to match to a local field (in the current search) to get the lookup document. When there is no lookup document matching it is a no-op. If there is more than one an exception is thrown.
 * local-lookup-field: optional. the name of a field in the current search to match against the lookup-field. **Default:** value of lookup-field.
-* appendonly: optional. indicates if the values to copy over to the search result from the lookup document should overwrite existing values. If true no existing values are overwritten. **Default:** false.
+* overwrite: optional. indicates if the values to copy over to the search result from the lookup document should overwrite existing values. If true no existing values are overwritten. **Default:** false.
 * source-field: optional. the fields to copy over from the lookup document to the search result. If no such fields are given all fields are copied. **Default:** all fields
 * local-source-field: optional. the final name of the field in the search result (if different from the field name in the lookup document). **Default:** value of source-field.
 
@@ -125,7 +125,7 @@ PPL query::
     | 21               | NULL         | finance    | false  |
     +------------------+--------------+------------+--------+
 
-    os> source=accounts | lookup hr employee_number AS account_number, dep AS department appendonly=true;
+    os> source=accounts | lookup hr employee_number AS account_number, dep AS department overwrite=true;
     fetched rows / total rows = 4/4
     +------------------+----------+------------------+------------+-----------+---------+-----------------+
     | account_number   | gender   | name             | department | active    | dep     | employee_number |
@@ -136,7 +136,7 @@ PPL query::
     | 21               | F        | Mandy Smith      | it         | NULL      | it      | 21              |
     +------------------+----------+------------------+------------+-----------+---------+-----------------+
 
-    os> source=accounts | lookup hr employee_number AS account_number, dep AS department appendonly=false;
+    os> source=accounts | lookup hr employee_number AS account_number, dep AS department overwrite=false;
     fetched rows / total rows = 4/4
     +------------------+----------+------------------+------------+-----------+---------+-----------------+
     | account_number   | gender   | name             | department | active    | dep     | employee_number |
diff --git a/integ-test/src/test/java/org/opensearch/sql/ppl/LookupCommandIT.java b/integ-test/src/test/java/org/opensearch/sql/ppl/LookupCommandIT.java
index d6a85f4687..1353cf7ddf 100644
--- a/integ-test/src/test/java/org/opensearch/sql/ppl/LookupCommandIT.java
+++ b/integ-test/src/test/java/org/opensearch/sql/ppl/LookupCommandIT.java
@@ -170,7 +170,7 @@ public void testLookupSelectedMultipleAttributes() throws IOException {
   }
 
   @Test
-  public void testLookupShouldAppendOnlyShouldBeFalseByDefault() throws IOException {
+  public void testLookupShouldOverwriteShouldBeFalseByDefault() throws IOException {
     JSONObject result =
         executeQuery(
             String.format(
@@ -212,11 +212,11 @@ public void testLookupShouldAppendOnlyShouldBeFalseByDefault() throws IOExceptio
   }
 
   @Test
-  public void testLookupWithAppendOnlyFalse() throws IOException {
+  public void testLookupWithOverwriteFalse() throws IOException {
     JSONObject result =
         executeQuery(
             String.format(
-                "source=%s | rename temperature as vendor | lookup %s did as device-id appendonly ="
+                "source=%s | rename temperature as vendor | lookup %s did as device-id overwrite ="
                     + " true | sort @timestamp",
                 TEST_INDEX_IOT_READINGS, TEST_INDEX_IOT_SENSORS));
     verifyDataRows(