D vs large integer

D and large integer both are nouns.

Word	Noun	Adjective	Verb	Adverb
D	Yes	No	No	No
large integer	Yes	No	No	No

As nouns, large integer is a hypernym of D; that is, large integer is a word with a broader meaning than D:

D (noun)	large integer (noun)
the 4th letter of the Roman alphabet	an integer equal to or greater than ten
the cardinal number that is the product of one hundred and five
a fat-soluble vitamin that prevents rickets