diff --git a/toolchain/check/BUILD b/toolchain/check/BUILD
index 00ff18a3b325..4519deae232a 100644
--- a/toolchain/check/BUILD
+++ b/toolchain/check/BUILD
@@ -34,7 +34,7 @@ cc_library(
         "check.cpp",
         "context.cpp",
         "convert.cpp",
-        "declaration_name_stack.cpp",
+        "decl_name_stack.cpp",
         "inst_block_stack.cpp",
         "return.cpp",
         "return.h",
@@ -47,7 +47,7 @@ cc_library(
         "check.h",
         "context.h",
         "convert.h",
-        "declaration_name_stack.h",
+        "decl_name_stack.h",
         "inst_block_stack.h",
         "pending_block.h",
     ],
diff --git a/toolchain/check/context.cpp b/toolchain/check/context.cpp
index 4ec13e429c28..ef961e67ea3d 100644
--- a/toolchain/check/context.cpp
+++ b/toolchain/check/context.cpp
@@ -10,7 +10,7 @@
 #include "common/check.h"
 #include "common/vlog.h"
 #include "llvm/ADT/Sequence.h"
-#include "toolchain/check/declaration_name_stack.h"
+#include "toolchain/check/decl_name_stack.h"
 #include "toolchain/check/inst_block_stack.h"
 #include "toolchain/lex/tokenized_buffer.h"
 #include "toolchain/parse/node_kind.h"
diff --git a/toolchain/check/context.h b/toolchain/check/context.h
index 3ce6a1f95494..df54c76769bb 100644
--- a/toolchain/check/context.h
+++ b/toolchain/check/context.h
@@ -9,7 +9,7 @@
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/SmallVector.h"
-#include "toolchain/check/declaration_name_stack.h"
+#include "toolchain/check/decl_name_stack.h"
 #include "toolchain/check/inst_block_stack.h"
 #include "toolchain/check/node_stack.h"
 #include "toolchain/parse/tree.h"
diff --git a/toolchain/check/declaration_name_stack.cpp b/toolchain/check/decl_name_stack.cpp
similarity index 99%
rename from toolchain/check/declaration_name_stack.cpp
rename to toolchain/check/decl_name_stack.cpp
index c45a860218dc..9bc3a7f8f776 100644
--- a/toolchain/check/declaration_name_stack.cpp
+++ b/toolchain/check/decl_name_stack.cpp
@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include "toolchain/check/declaration_name_stack.h"
+#include "toolchain/check/decl_name_stack.h"
 
 #include "toolchain/check/context.h"
 
diff --git a/toolchain/check/declaration_name_stack.h b/toolchain/check/decl_name_stack.h
similarity index 97%
rename from toolchain/check/declaration_name_stack.h
rename to toolchain/check/decl_name_stack.h
index 7b15130ae57a..aab00939a7cd 100644
--- a/toolchain/check/declaration_name_stack.h
+++ b/toolchain/check/decl_name_stack.h
@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#ifndef CARBON_TOOLCHAIN_CHECK_DECLARATION_NAME_STACK_H_
-#define CARBON_TOOLCHAIN_CHECK_DECLARATION_NAME_STACK_H_
+#ifndef CARBON_TOOLCHAIN_CHECK_DECL_NAME_STACK_H_
+#define CARBON_TOOLCHAIN_CHECK_DECL_NAME_STACK_H_
 
 #include "llvm/ADT/SmallVector.h"
 #include "toolchain/parse/tree.h"
@@ -198,4 +198,4 @@ class DeclNameStack {
 
 }  // namespace Carbon::Check
 
-#endif  // CARBON_TOOLCHAIN_CHECK_DECLARATION_NAME_STACK_H_
+#endif  // CARBON_TOOLCHAIN_CHECK_DECL_NAME_STACK_H_
diff --git a/toolchain/check/handle_call_expression.cpp b/toolchain/check/handle_call_expr.cpp
similarity index 100%
rename from toolchain/check/handle_call_expression.cpp
rename to toolchain/check/handle_call_expr.cpp
diff --git a/toolchain/check/handle_expression_statement.cpp b/toolchain/check/handle_expr_statement.cpp
similarity index 100%
rename from toolchain/check/handle_expression_statement.cpp
rename to toolchain/check/handle_expr_statement.cpp
diff --git a/toolchain/check/handle_if_expression.cpp b/toolchain/check/handle_if_expr.cpp
similarity index 100%
rename from toolchain/check/handle_if_expression.cpp
rename to toolchain/check/handle_if_expr.cpp
diff --git a/toolchain/lower/handle_expression_category.cpp b/toolchain/lower/handle_expr_category.cpp
similarity index 100%
rename from toolchain/lower/handle_expression_category.cpp
rename to toolchain/lower/handle_expr_category.cpp
diff --git a/toolchain/parse/handle_array_expression.cpp b/toolchain/parse/handle_array_expr.cpp
similarity index 100%
rename from toolchain/parse/handle_array_expression.cpp
rename to toolchain/parse/handle_array_expr.cpp
diff --git a/toolchain/parse/handle_brace_expression.cpp b/toolchain/parse/handle_brace_expr.cpp
similarity index 100%
rename from toolchain/parse/handle_brace_expression.cpp
rename to toolchain/parse/handle_brace_expr.cpp
diff --git a/toolchain/parse/handle_call_expression.cpp b/toolchain/parse/handle_call_expr.cpp
similarity index 100%
rename from toolchain/parse/handle_call_expression.cpp
rename to toolchain/parse/handle_call_expr.cpp
diff --git a/toolchain/parse/handle_declaration_name_and_params.cpp b/toolchain/parse/handle_decl_name_and_params.cpp
similarity index 100%
rename from toolchain/parse/handle_declaration_name_and_params.cpp
rename to toolchain/parse/handle_decl_name_and_params.cpp
diff --git a/toolchain/parse/handle_declaration_scope_loop.cpp b/toolchain/parse/handle_decl_scope_loop.cpp
similarity index 100%
rename from toolchain/parse/handle_declaration_scope_loop.cpp
rename to toolchain/parse/handle_decl_scope_loop.cpp
diff --git a/toolchain/parse/handle_expression.cpp b/toolchain/parse/handle_expr.cpp
similarity index 100%
rename from toolchain/parse/handle_expression.cpp
rename to toolchain/parse/handle_expr.cpp
diff --git a/toolchain/parse/handle_index_expression.cpp b/toolchain/parse/handle_index_expr.cpp
similarity index 100%
rename from toolchain/parse/handle_index_expression.cpp
rename to toolchain/parse/handle_index_expr.cpp
diff --git a/toolchain/parse/handle_paren_expression.cpp b/toolchain/parse/handle_paren_expr.cpp
similarity index 100%
rename from toolchain/parse/handle_paren_expression.cpp
rename to toolchain/parse/handle_paren_expr.cpp