reader vs bookworm

reader and bookworm both are nouns.

Word	Noun	Adjective	Verb	Adverb
reader	Yes	No	No	No
bookworm	Yes	No	No	No

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

reader (noun)	bookworm (noun)
one of a series of texts for students learning to read	someone who spends a great deal of time reading
a person who enjoys reading	a person who pays more attention to formal rules and book learning than they merit
a public lecturer at certain universities
someone who contracts to receive and pay for a service or a certain number of issues of a publication
a person who can read; a literate person
someone who reads proof in order to find errors and mark corrections
someone who reads manuscripts and judges their suitability for publication
someone who reads the lessons in a church service; someone ordained in a minor order of the Roman Catholic Church