diff --git a/lamb/commands.py b/lamb/commands.py
index f978418..8886308 100644
--- a/lamb/commands.py
+++ b/lamb/commands.py
@@ -1,4 +1,5 @@
 from prompt_toolkit.formatted_text import FormattedText
+from prompt_toolkit.formatted_text import HTML
 from prompt_toolkit.shortcuts import clear as clear_screen
 
 from lamb.runstatus import CommandStatus
@@ -16,11 +17,29 @@ def lamb_command(*, help_text: str):
 	return inner
 
 def run(command, runner):
-	return commands[command](runner)
+	return commands[command.name](command, runner)
 
+@lamb_command(help_text = "Delete a macro")
+def mdel(command, runner):
+	if len(command.args) != 1:
+		return CommandStatus(
+			formatted_text = HTML(
+				"<red>Command <grey>:mdel</grey> takes exactly one argument.</red>"
+			)
+		)
+
+	target = command.args[0]
+	if target not in runner.macro_table:
+		return CommandStatus(
+			formatted_text = HTML(
+				f"<red>Macro \"{target}\" is not defined</red>"
+			)
+		)
+
+	del runner.macro_table[target]
 
 @lamb_command(help_text = "Show macros")
-def macros(runner):
+def macros(command, runner):
 	return CommandStatus(
 		formatted_text = FormattedText([
 			("#FF6600 bold", "\nDefined Macros:\n"),
@@ -33,13 +52,13 @@ def macros(runner):
 	)
 
 @lamb_command(help_text = "Clear the screen")
-def clear(runner):
+def clear(command, runner):
 	clear_screen()
 	utils.show_greeting()
 
 
 @lamb_command(help_text = "Print this help")
-def help(runner):
+def help(command, runner):
 	return CommandStatus(
 		formatted_text = FormattedText([
 			("#FF6600 bold", "\nUsage:\n"),
diff --git a/lamb/parser.py b/lamb/parser.py
index 88ffd07..afeca05 100755
--- a/lamb/parser.py
+++ b/lamb/parser.py
@@ -56,7 +56,7 @@ class Parser:
 		(lp + pp_call + rp)
 	)
 
-	pp_command = pp.Suppress(":") + pp.Word(pp.alphas + "_")
+	pp_command = pp.Suppress(":") + pp.Word(pp.alphas + "_") + pp.Word(pp.alphas + "_")[0, ...]
 	pp_command.set_parse_action(tokens.command.from_parse)
 
 
diff --git a/lamb/runner.py b/lamb/runner.py
index 29957c4..58db6e4 100644
--- a/lamb/runner.py
+++ b/lamb/runner.py
@@ -1,3 +1,4 @@
+from distutils.cmd import Command
 from prompt_toolkit.formatted_text import FormattedText
 
 import lamb.commands as commands
@@ -15,8 +16,8 @@ class Runner:
 		# If None, no maximum is enforced.
 		self.reduction_limit: int | None = 300
 
-	def exec_command(self, command: str) -> rs.CommandStatus:
-		if command in commands.commands:
+	def exec_command(self, command: tokens.command) -> rs.CommandStatus:
+		if command.name in commands.commands:
 			return commands.run(command, self)
 
 		# Handle unknown commands
@@ -80,7 +81,7 @@ class Runner:
 
 		# If this line is a command, do the command.
 		elif isinstance(e, tokens.command):
-			return self.exec_command(e.name)
+			return self.exec_command(e)
 
 		# If this line is a plain expression, reduce it.
 		elif isinstance(e, tokens.LambdaToken):
diff --git a/lamb/tokens.py b/lamb/tokens.py
index 51b2f80..05dadcb 100755
--- a/lamb/tokens.py
+++ b/lamb/tokens.py
@@ -81,10 +81,12 @@ class command:
 	def from_parse(result):
 		return command(
 			result[0],
+			result[1:]
 		)
 
-	def __init__(self, name):
+	def __init__(self, name, args):
 		self.name = name
+		self.args = args
 
 class macro(LambdaToken):
 	"""