crammer vs textbook

crammer and textbook both are nouns.

Word	Noun	Adjective	Verb	Adverb
crammer	Yes	No	No	No
textbook	Yes	Yes	No	No

As nouns, textbook is a hypernym of crammer; that is, textbook is a word with a broader meaning than crammer:

Other hypernyms of crammer include school text, schoolbook, text, text edition.

crammer (noun)	textbook (noun)
a textbook designed for cramming	a book prepared for use in schools or colleges
a special school where students are crammed
a student who crams
a teacher who is paid to cram students for examinations

crammer (adjective)	textbook (adjective)
	according to or characteristic of a casebook or textbook; typical