citrus vs orange

citrus and orange both are nouns.

Word	Noun	Adjective	Verb	Adverb
citrus	Yes	No	No	No
orange	Yes	Yes	No	No

As nouns, orange is a hyponym of citrus; that is, orange is a word with a more specific, narrower meaning than citrus:

citrus: any of numerous fruits of the genus Citrus having thick rind and juicy pulp; grown in warm regions
orange: round yellow to orange fruit of any of several citrus trees

As nouns, orange is a hyponym of citrus; that is, orange is a word with a more specific, narrower meaning than citrus:

citrus: any of numerous tropical usually thorny evergreen trees of the genus Citrus having leathery evergreen leaves and widely cultivated for their juicy edible fruits having leathery aromatic rinds
orange: any citrus tree bearing oranges

citrus (noun)	orange (noun)
any of numerous fruits of the genus Citrus having thick rind and juicy pulp; grown in warm regions	orange color or pigment; any of a range of colors between red and yellow
any of numerous tropical usually thorny evergreen trees of the genus Citrus having leathery evergreen leaves and widely cultivated for their juicy edible fruits having leathery aromatic rinds	round yellow to orange fruit of any of several citrus trees
	any citrus tree bearing oranges
	any pigment producing the orange color

citrus (adjective)	orange (adjective)
	of the color between red and yellow; similar to the color of a ripe orange