Connor Creagan alien al⋅ien [eyl-yuhn, ey-lee-uhn] –noun 1. a resident born in or belonging to another country who has not acquired citizenship by naturalization (distinguished from citizen). 2. a foreigner. 3. a person who has been estranged or excluded. 4. a creature from outer space; extraterrestrial. –adjective 5. unlike one's own; strange; not belonging to one: alien speech. a home a b c d e f g h i j k l m n o p q r s t u v w x y z abandon abundance absence advertisement access ache afterthought airport album alien all-art air-vent afro