The reason it might seem "real" is because:
* It's a common mistake: Many people accidentally say or write "eleventeen" instead of "eleven" due to the similarity in sound and spelling. This makes it seem like a familiar word, even though it's not.
* It's often used in humor: Comedians and writers often use "eleventeen" for comedic effect, highlighting the absurdity of the misspelling and creating a humorous sense of familiarity.
* It's a fun play on language: The misspelling plays on the established pattern of counting numbers, making it sound almost plausible.
So, while "eleventeen" doesn't have a place in the dictionary, it's a fun word that captures the common mistakes and humor of language.