Definition of "apparition" []

• A ghostly figure; a specter. (noun)
• A sudden or unusual sight: "[The designer's] indoor-outdoor reversals and juxtapositions call forth a Magritte apparition beneath a Miami moon” ( Herbert Muschamp). (noun)
• The act of appearing; appearance. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "At other moments in the narrative, the haunting of the apparition is achieved solely through the powers of the voice — en route to the Villa Altieri, for example, a voice entirely lacking in any visually identifiable origin emanates as if from nowhere, at once betraying the uncanny presence of Vivaldi's ghostly companion as well as maintaining his invisibility:"
• "These aren't pluralizations, which should be obvious from the examples. (e.g. the plural of apparition is apparitions.)"
• "The visual aspect is not all of it—hence the misleading term apparition."