grapefruit vs Citrus paradisi

grapefruit and Citrus paradisi both are nouns.

Word	Noun	Adjective	Verb	Adverb
grapefruit	Yes	No	No	No
Citrus paradisi	Yes	No	No	No

As nouns, grapefruit and Citrus paradisi are synonyms defined as:

grapefruit and Citrus paradisi: citrus tree bearing large round edible fruit having a thick yellow rind and juicy somewhat acid pulp

grapefruit (noun)	Citrus paradisi (noun)
large yellow fruit with somewhat acid juicy pulp; usual serving consists of a half	citrus tree bearing large round edible fruit having a thick yellow rind and juicy somewhat acid pulp
citrus tree bearing large round edible fruit having a thick yellow rind and juicy somewhat acid pulp