Super is a keyword.

CoffeeScript.tmLanguage

@@ -237,7 +237,7 @@
 			<string>(?x)
 				and=|or=|!|%|&amp;|\^|\*|\/|(\-)?\-(?!&gt;)|\+\+|\+|~|==|=(?!&gt;)|!=|&lt;=|&gt;=|&lt;&lt;=|&gt;&gt;=|
 				&gt;&gt;&gt;=|&lt;&gt;|&lt;|&gt;|!|&amp;&amp;|\.\.(\.)?|\?|\||\|\||\:|\*=|(?&lt;!\()/=|%=|\+=|\-=|&amp;=|
-				\^=|\b(?&lt;![\.\$])(instanceof|new|delete|typeof|and|or|is|isnt|not)\b
+				\^=|\b(?&lt;![\.\$])(instanceof|new|delete|typeof|and|or|is|isnt|not|super)\b
 			</string>
 			<key>name</key>
 			<string>keyword.operator.coffee</string>
@@ -392,7 +392,7 @@
 		</dict>
 		<dict>
 			<key>match</key>
-			<string>\b(?&lt;!\.)(super|this|extends)(?!\s*[:=])\b</string>
+			<string>\b(?&lt;!\.)(this|extends)(?!\s*[:=])\b</string>
 			<key>name</key>
 			<string>variable.language.coffee</string>
 		</dict>