HyperDic: hour_circle

English > 1 sense of the expression *hour circle*:
NOUN	location	hour circle	a great circle on the celestial sphere that passes through both celestial poles

English > *hour circle*: 1 sense > noun 1, location
Meaning	A great circle on the celestial sphere that passes through both celestial poles.
Broader	great circle	A circular line on the surface of a sphere formed by intersecting it with a plane passing through the center