1. a ghost or spirit of a dead person
2. something that haunts or disturbs the mind; a disturbing possibility

Examples

• The old castle was said to be haunted by the spectre of its former owner.
• She claimed to have seen a pale spectre wandering the halls at midnight.
• The spectre of unemployment loomed over the factory workers.
• The spectre of war cast a shadow over the peace negotiations.
• His past mistakes returned like a spectre to haunt him.
• The spectre of economic collapse worried investors worldwide.