the spirit of a dead person that some people think they can feel or see in a place ➔ Holy Ghost
the ghost of Old Tom Morris
They say the young girl's ghost still haunts (=often appears in) the house.
He looked as if he'd seen a ghost (=he looked very frightened).
the memory or effect of someone or something bad that lived, existed, or happened in the past
The ghost of Stalinism still affects life in Russia today.
a smile etc that is so slight you are not sure it happened:
The ghost of a smile flitted across her sad features.
a second image that is not clear on a television or computer screen
if a machine gives up the ghost, it does not work any more and cannot be repaired - used humorously:
Unfortunately, my car's just given up the ghost.