hourglass:1

noun
hour*glass \ ˈau̇(-ə)r-ˌglas \
circa 1515
  • an instrument for measuring time consisting of a glass vessel having two compartments from the upper of which a quantity of usually sand runs in an hour into the lower one

hourglass:2

adjective
hourglass \
circa 1834
  • shaped like an hourglass
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