The quality or state of being dreamlike; resemblance to a dream.
From dreamlike + -ness. This is a double nominalization: dream becomes dreamlike (adjective), which then becomes dreamlikeness (noun), a common English pattern for expressing abstract qualities.
Medieval philosophers puzzled over dreamlikeness as evidence for the unreality of waking life itself—this idea influenced entire philosophical traditions and later inspired the movie 'The Matrix,' which asks whether our waking world might actually be a simulation.
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