Lewis & Short

ālūcĭnātĭo (all- or hall-), ōnis, f. [alucinor], a wandering of mind, dreaminess, revery (acc. to Non. 121, 20, used even by the old writers (veteres); but, except in the passage quoted by him from an author not named, it is found only in the foll. exs.), Sen. Vit. Beat. 26; Arn. 4, p. 152, and 6, p. 194.