What does "sandglass" mean?

An instrument for measuring the passage of time by the passage of sand through a narrow opening.

What is a synonym for "sandglass"?

Common synonyms include: hourglass, hourglasses, sand clock, sand timer, time metaphor, time symbol.

noun

noun ·Rare ·Advanced level

Noun

1
An instrument for measuring the passage of time by the passage of sand through a narrow opening.
2
timepiece in which the passage of time is indicated by the flow of sand from one transparent container to another through a narrow passage wordnet

From sand + glass.