noun — 2 senses
Etymology From ghost (noun sense 3, via noun sense 4).
Arts, Hobbies, Lifestyle, Photography Any undesired image appearing at the image plane of an optical system; either a false image of the desired object, or an out-of-focus image of a bright source of light in the field of the optical system.
Etymology After the Norton Ghost disk-cloning and backup software tool, itself an initialism of general hardware-oriented system transfer.
Computing, Engineering, Mathematics, Natural sciences, Physical sciences, Sciences A copy of all the contents of a hard drive, used as a backup.
Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.