comprehend vs register

comprehend is not a noun while register is a noun.

Word	Noun	Adjective	Verb	Adverb
comprehend	No	No	Yes	No
register	Yes	No	Yes	No

comprehend (noun)	register (noun)
	a regulator (as a sliding plate) for regulating the flow of air into a furnace or other heating device
	an air passage (usually in the floor or a wall of a room) for admitting or excluding heated air from the room
	a cashbox with an adding machine to register transactions; used in shops to add up the bill
	(computer science) memory device that is the part of computer memory that has a specific address and that is used to hold information of a specific kind
	(music) the timbre that is characteristic of a certain range and manner of production of the human voice or of different pipe organ stops or of different musical instruments
	an official written record of names or events or transactions
	a book in which names and transactions are listed

comprehend (verb)	register (verb)
get the meaning of something	enter into someone's consciousness
to become aware of through the senses	indicate a certain reading; of gauges and instruments
include in scope; include as part of something broader; have as one's sphere or territory	record in a public office or in a court of law
	send by registered mail
	manipulate the registers of an organ
	be aware of
	show in one's face
	record in writing; enter into a book of names or events or transactions
	enroll to vote
	have one's name listed as a candidate for several parties