dark vs mean solar day

dark and mean solar day both are nouns.

Word	Noun	Adjective	Verb	Adverb
dark	Yes	Yes	No	No
mean solar day	Yes	No	No	No

dark (noun)	mean solar day (noun)
an unenlightened state	time for Earth to make a complete rotation on its axis
an unilluminated area
absence of light or illumination
absence of moral or spiritual values
the time after sunset and before sunrise while it is dark outside

dark (adjective)	mean solar day (adjective)
devoid of or deficient in light or brightness; shadowed or black
(used of color) having a dark hue
brunet (used of hair or skin or eyes)
secret
causing dejection
stemming from evil characteristics or forces; wicked or dishonorable
showing a brooding ill humor
not giving performances; closed
marked by difficulty of style or expression
lacking enlightenment or knowledge or culture