Ghost is a movie starring Demi Moore and Patrick Swayze
In quantum field theory, ghosts are a auxiliary fields needed in non-abeliangauge theories in order to deal with the gauge freedom. Although they are real fields, ghosts follow fermionic statistics. They are only artifacts of the theory, and do not correspond to real particles.
A ghost is any image on a tv screen that doesn't belong to the programme in question.
Ghost is a computer disk cloning program, originally produced by Binary Research in Auckland, New Zealand, and acquired by Symantec in June 1998. Development is still based in Auckland.
Ghosts are also a name for the structures that form when blood is submerged in water. The red blood cells explode, leaving small spheres of phospholipids. These are the "ghosts".
A ghostwriter is an author who writes under someone else's name.