noun: 1. an inhabitant; occupant; resident: denizens of the forest. 2. a person or one who/that regularly frequents a place; habitué: the denizens of a local bar; nightclub denizens. 3. a naturalized foreign word. verb: 1. to make a denizen of. in government: a person admitted to residence in a foreign country especially : an alien (see below) admitted to rights of citizenship. alien: a foreign-born resident who has not been naturalized and is still a subject or citizen of a foreign country; broadly : a foreign-born citizen. British: 1. an alien admitted to residence and to certain rights of citizenship in a country. 2. an individual permanently resident in a foreign country where he enjoys certain rights of citizenship. of animals and plants: 1. anything adapted to a new place, condition, etc., as an animal or plant not indigenous to a place but successfully naturalized. 2. a plant or animal established in a place to which it is not native. Example: the polar bear is an iconic denizen of the snowy Arctic. Related Words: inhabitant, occupant, dweller, national, habitant, native, citizen, subject, liver, indweller, inhabiter, resider. Synonyms: familiar, frequenter, habitué (also habitue), haunter, rat, regular. Origin: 1425–75; late Middle English denisein < Anglo-French, equivalent to deinz within (Old French; see dedans) + -ein -an. C15: from Anglo-French denisein, from Old French denzein, from denz within, from Latin de intus from within. First Known Use: 15th century. History and Etymology: Middle English denizeine, from Anglo-French denisein, denzein inhabitant, inner part, inner, from denz within, from Late Latin deintus, from Latin de- + intus within — more at ent-. Source 1, Source 2.