The quality or state of being ghostlike; resemblance to a ghost in appearance, substance, or behavior.
From 'ghostlike' (ghost + -like) plus '-ness,' a suffix creating abstract nouns. The -ness suffix is one of English's most productive ways to transform adjectives into abstract concepts.
English's -ness suffix is magically productive—you can add it to almost any adjective and create a new noun, which is why we have words for feelings that other languages can't easily name!
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