the soul of a dead person, a disembodied spirit imagined, usually as a vague, shadowy or evanescent form, as wandering among or haunting living persons.

a mere shadow or semblance; a trace

He's a ghost of his former self.

a remote possibility

He hasn't a ghost of a chance.

( sometimes initial capital letter ) a spiritual being.

the principle of life; soul; spirit.

Informal . ghost writer.

a secondary image, esp. one appearing on a television screen as a white shadow, caused by poor or double reception or by a defect in the receiver.

Also called ghost image. Photography . a faint secondary or out-of-focus image in a photographic print or negative resulting from reflections within the camera lens.

an oral word game in which each player in rotation adds a letter to those supplied by preceding players, the object being to avoid ending a word.

Optics . a series of false spectral lines produced by a diffraction grating with unevenly spaced lines.

Metalworking . a streak appearing on a freshly machined piece of steel containing impurities.

a red blood cell having no hemoglobin.

a fictitious employee, business, etc., fabricated esp. for the purpose of manipulating funds or avoiding taxes

Investigation showed a payroll full of ghosts.

to ghostwrite (a book, speech, etc.).

to haunt.

Engraving . to lighten the background of (a photograph) before engraving.

to ghostwrite.

to go about or move like a ghost.

(of a sailing vessel) to move when there is no perceptible wind.

to pay people for work not performed, esp. as a way of manipulating funds.

fabricated for purposes of deception or fraud

We were making contributions to a ghost company.

give up the ghost

to die.

to cease to function or exist.

adjective

cadaverous , deadly , deathlike , deathly , ghostly , spectral