Hourglass

ឃ្លាដែលទាក់ទង

• hourglass contraction
  - សភាពដែលសរីរាង្គមួយផ្នែកកណ្ដាល

1.

An instrument for measuring time, especially the interval of an hour. It consists of a glass vessel having two compartments, from the uppermost of which a quantity of sand, water, or mercury occupies an hour in running through a small aperture unto the lower.