crammer vs cram

crammer is a noun but cram is not a noun.

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

crammer (noun)	cram (noun)
a textbook designed for cramming
a special school where students are crammed
a student who crams
a teacher who is paid to cram students for examinations

crammer (verb)	cram (verb)
	prepare (students) hastily for an impending exam
	study intensively, as before an exam
	crowd or pack to capacity
	put something somewhere so that the space is completely filled