circummeridian

As a noun terms

is .

As an adjective circummeridian is

(astronomy) about or around the meridian.

In astronomy terms the difference between meridian and circummeridian

is that meridian is a great circle passing through the poles of the celestial sphere and the zenith for a particular observer while circummeridian is about or around the meridian.

As adjectives the difference between meridian and circummeridian

is that meridian is meridional; relating to a meridian while circummeridian is about or around the meridian.

As a noun meridian

is an imaginary great circle on the Earth's surface, passing through the geographic poles.

As a proper noun Meridian

is a CDP in Colorado.