mandarin orange vs citrus

mandarin orange and citrus both are nouns.

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

As nouns, citrus is a hypernym of mandarin orange; that is, citrus is a word with a broader meaning than mandarin orange:

mandarin orange: a somewhat flat reddish-orange loose skinned citrus of China
citrus: any of numerous fruits of the genus Citrus having thick rind and juicy pulp; grown in warm regions

Other hypernyms of mandarin orange include citrous fruit, citrus fruit.

As nouns, citrus is a hypernym of mandarin orange; that is, citrus is a word with a broader meaning than mandarin orange:

mandarin orange: shrub or small tree having flattened globose fruit with very sweet aromatic pulp and thin yellow-orange to flame-orange rind that is loose and easily removed; native to southeastern Asia
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

Other hypernyms of mandarin orange include citrus tree.

mandarin orange (noun)	citrus (noun)
a somewhat flat reddish-orange loose skinned citrus of China	any of numerous fruits of the genus Citrus having thick rind and juicy pulp; grown in warm regions
shrub or small tree having flattened globose fruit with very sweet aromatic pulp and thin yellow-orange to flame-orange rind that is loose and easily removed; native to southeastern Asia	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