diff --git a/ueforth/Makefile b/ueforth/Makefile
index d2d16ac..e4faa21 100644
--- a/ueforth/Makefile
+++ b/ueforth/Makefile
@@ -113,7 +113,7 @@ unit_tests: $(POSIX)/ueforth common/all_tests.fs
 $(GEN):
 	mkdir -p $@
 
-POSIX_BOOT =  common/boot.fs common/ansi.fs \
+POSIX_BOOT =  common/boot.fs common/vocabulary.fs common/ansi.fs \
               posix/posix.fs posix/posix_highlevel.fs \
               common/highlevel.fs common/filetools.fs posix/posix_desktop.fs \
               common/tasks.fs common/streams.fs common/blocks.fs posix/args.fs \
@@ -121,14 +121,14 @@ POSIX_BOOT =  common/boot.fs common/ansi.fs \
 $(GEN)/posix_boot.h: common/source_to_string.js $(POSIX_BOOT) | $(GEN)
 	echo "ok" | cat $(POSIX_BOOT) - | $< boot >$@
 
-WINDOWS_BOOT = common/boot.fs common/ansi.fs \
+WINDOWS_BOOT = common/boot.fs common/vocabulary.fs common/ansi.fs \
                windows/windows.fs windows/windows_highlevel.fs common/highlevel.fs \
                common/tasks.fs common/streams.fs common/blocks.fs \
                common/utils.fs
 $(GEN)/windows_boot.h: common/source_to_string.js $(WINDOWS_BOOT) | $(GEN)
 	echo "ok" | cat $(WINDOWS_BOOT) - | $< boot >$@
 
-ARDUINO_BOOT = common/boot.fs arduino/arduino.fs \
+ARDUINO_BOOT = common/boot.fs common/vocabulary.fs arduino/arduino.fs \
                posix/posix_highlevel.fs common/highlevel.fs common/filetools.fs \
                common/tasks.fs common/streams.fs arduino/arduino_server.fs \
                arduino/esp_camera.fs common/blocks.fs common/utils.fs \
diff --git a/ueforth/common/all_tests.fs b/ueforth/common/all_tests.fs
index 8e4bdb9..7d9d80a 100644
--- a/ueforth/common/all_tests.fs
+++ b/ueforth/common/all_tests.fs
@@ -2,4 +2,5 @@ include common/testing.fs
 include common/utils.fs
 include common/base_tests.fs
 include common/utils_tests.fs
+include common/vocabulary_tests.fs
 run-tests
diff --git a/ueforth/common/core.h b/ueforth/common/core.h
index c435aaf..2bcd428 100644
--- a/ueforth/common/core.h
+++ b/ueforth/common/core.h
@@ -127,8 +127,13 @@ static void ueforth_init(int argc, char *argv[], void *heap,
   g_sys.heap = (cell_t *) heap + 4;  // Leave a little room.
   cell_t *sp = g_sys.heap + 1; g_sys.heap += STACK_SIZE;
   cell_t *rp = g_sys.heap + 1; g_sys.heap += STACK_SIZE;
+
+  // FORTH vocabulary
+  *g_sys.heap++ = 0;
   g_sys.current = (cell_t **) g_sys.heap;
   g_sys.context = (cell_t **) g_sys.heap;  ++g_sys.heap;
+  *g_sys.heap++ = 0;  *g_sys.heap++ = 0;  *g_sys.heap++ = 0;
+
   ueforth_run(0);
   (*g_sys.current)[-1] = 1;  // Make last word ; IMMEDIATE
   g_sys.DOLIT_XT = FIND("DOLIT");
diff --git a/ueforth/common/vocabulary.fs b/ueforth/common/vocabulary.fs
new file mode 100644
index 0000000..7b79887
--- /dev/null
+++ b/ueforth/common/vocabulary.fs
@@ -0,0 +1,4 @@
+( Implement Vocabularies )
+: forth    [ current @ ] literal context ! ;
+: vocabulary ( "name" ) create 0 , current @ 2 cells + , does> cell+ context ! ;
+: definitions   context @ current ! ;
diff --git a/ueforth/common/vocabulary_tests.fs b/ueforth/common/vocabulary_tests.fs
new file mode 100644
index 0000000..858b157
--- /dev/null
+++ b/ueforth/common/vocabulary_tests.fs
@@ -0,0 +1,13 @@
+e: test-vocabularies
+  vocabulary foo
+  vocabulary bar
+  foo definitions : test ." AAAA" cr ;
+  bar definitions : test ." BBBB" cr ;
+  forth definitions
+  foo test
+  bar test
+  foo test
+  out: AAAA
+  out: BBBB
+  out: AAAA
+;e