Definitions

1. noun

A hypothetical instrument used to see into the future by observing the sun at the moment of sunrise on the summer solstice, in ancient Greek and Roman astronomy.

“In ancient Greek astronomy, the haloscope was believed to have the power to reveal the future.”

2. noun

A device or instrument, often used in science fiction, for viewing the past, present, or future, similar to a crystal ball or scrying glass.

“The old wizard claimed to possess a magical haloscope that allowed him to see glimpses of the future.”