Demonyms do not always clearly distinguish place of origin or ethnicity from place of residence or citizenship, and many demonyms overlap with the ethnonym for the ethnically dominant group of a region. Thus a Thai may be any resident or citizen of Thailand of any ethnic group, or more narrowly a member of the Thai people.
Conversely, some groups of people may be associated with multiple demonyms. For example, a native of the United Kingdom may be called a British person, a Briton or, informally, a Brit. In some languages, a demonym may be borrowed from another language as a nickname or descriptive adjective for a group of people: for example, "Québécois(e)" is commonly used in English for a native of Quebec (though "Quebecker" is also available).
In English, demonyms are capitalized and are often the same as the adjectival form of the place, e.g. Egyptian, Japanese, or Greek. Significant exceptions exist; for instance, the adjectival form of Spain is "Spanish", but the demonym is "Spaniard".
English commonly uses national demonyms such as "Ethiopian" or "Guatemalan", while the usage of local demonyms such as "Chicagoan", "Okie", or "Parisian", is rare. Many local demonyms are rarely used and many places, especially smaller towns and cities, lack a commonly used and accepted demonym altogether.
The word gentilic comes from the Latingentilis ("of a clan, or gens") and the English suffix -ic. The word demonym was derived from the Greek word meaning "populace" (δῆμος, demos) with the suffix for "name" (-onym).
National Geographic attributes the term "demonym" to Merriam-Webster editor Paul Dickson in a recent work from 1990. The word did not appear for nouns, adjectives, and verbs derived from geographical names in the Merriam-Webster Collegiate Dictionary nor in prominent style manuals such as the Chicago Manual of Style. It was subsequently popularized in this sense in 1997 by Dickson in his book Labels for Locals. However, in What Do You Call a Person From...? A Dictionary of Resident Names (the first edition of Labels for Locals) Dickson attributed the term to George H. Scheetz, in his Names' Names: A Descriptive and Prescriptive Onymicon (1988), which is apparently where the term first appears. The term may have been fashioned after demonymic, which the Oxford English Dictionary defines as the name of an Atheniancitizen according to the deme to which the citizen belongs, with its first use traced to 1893.