Connecticutensian

The common way to form an adjective from a place-name in Medieval Latin was to a suffix -ensis to the root. For example, Berkeleiensis from Berkeley. So, it's something that a educated person in the 18th century would've known about and possibly chuckled over as the name in question is from a Native American language and the resulting adjectival form is macaronic.

Ceci n'est pas un seing.