sandglass vs timepiece

sandglass and timepiece both are nouns.

Word	Noun	Adjective	Verb	Adverb
sandglass	Yes	No	No	No
timepiece	Yes	No	No	No

As nouns, timepiece is a hypernym of sandglass; that is, timepiece is a word with a broader meaning than sandglass:

sandglass: timepiece in which the passage of time is indicated by the flow of sand from one transparent container to another through a narrow passage
timepiece: a measuring instrument or device for keeping time

Other hypernyms of sandglass include horologe, timekeeper.

sandglass (noun)	timepiece (noun)
timepiece in which the passage of time is indicated by the flow of sand from one transparent container to another through a narrow passage	a measuring instrument or device for keeping time