There’s a list of which words are real and which are fake on the wiki at <a href="http:&#x2F;&#x2F;www.explainxkcd.com&#x2F;wiki&#x2F;index.php&#x2F;1572:_xkcd_Survey#Difficult_words" rel="nofollow">http:&#x2F;&#x2F;www.explainxkcd.com&#x2F;wiki&#x2F;index.php&#x2F;1572:_xkcd_Survey#...</a>. The fake words aren’t even in the Oxford English Dictionary – I checked.