Muggle is a relatively new word with some interesting history. English is a living language, which means it changes over time. New words are constantly entering the language, evidenced by the Oxford English Dictionary’s policy of adding English words to their lexicon quarterly.
A muggle is someone who is uninformed concerning a particular activity, someone who does not have a particular skill, someone who is not part of a particular social or professional community. The word muggle, as it is used today, was coined by J.K. Rowling in her Harry Potter series of books. In the Harry Potter world, a muggle is someone who does not have magical powers. In the wizarding world, that would be a terrible deficit. Today, people who have a particular skill or are members of a particular community may refer to outsiders as muggles. For instance, knitters may call non-knitters muggles. Runners may call non-runners muggles. Academics may call blue collar workers muggles. The Oxford English Dictionary added the word muggle in 2003, with its current definition. Interestingly, the word muggle was used for a brief time in the 1600s to mean “honey” or “darling”.
“Wizards Unite” feels a little more contrived: you work for the Ministry of Magic, wandering about the world attempting to discover “foundables,” bits of magic paraphernalia and people that have been lost, frozen, or captured by dark forces and thus are at risk of having the muggle world discover them. (The St. George Daily Spectrum)
Ravi is a Muggle, someone with a non-horsey job (engineer), and as such keeps normal hours. (The Chronicle of the HOrse)
And despite the near-wondrous properties ascribed to MMT by its most fervent devotees, it’s derived from the decidedly muggle-esque observation that a government whose debt is in the currency it creates will never be unable to pay its bills unless it so chooses. (The Week Magazine)
Craft beer enthusiasts can argue points on the hop flavoring, but to a microbrew muggle, this drink just tastes like a carbonated cocktail mixer. (San Francisco Weekly)