octant vs measuring device

octant and measuring device both are nouns.

Word	Noun	Adjective	Verb	Adverb
octant	Yes	No	No	No
measuring device	Yes	No	No	No

As nouns, measuring device is a hypernym of octant; that is, measuring device is a word with a broader meaning than octant:

octant: a measuring instrument for measuring angles to a celestial body; similar to a sextant but with 45 degree calibration
measuring device: instrument that shows the extent or amount or quantity or degree of something

Other hypernyms of octant include measuring instrument, measuring system.

octant (noun)	measuring device (noun)
a measuring instrument for measuring angles to a celestial body; similar to a sextant but with 45 degree calibration	instrument that shows the extent or amount or quantity or degree of something