Citrus paradisi vs grapefruit

Citrus paradisi and grapefruit both are nouns.

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

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

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

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