plagiarize vs steal

plagiarize is not a noun while steal is a noun.

Word	Noun	Adjective	Verb	Adverb
plagiarize	No	No	Yes	No
steal	Yes	No	Yes	No

As verbs, steal is a hypernym of plagiarize; that is, steal is a word with a broader meaning than plagiarize:

plagiarize: take without referencing from someone else's writing or speech; of intellectual property
steal: take without the owner's consent

Other hypernyms of plagiarize include rip, rip off.

plagiarize (noun)	steal (noun)
	a stolen base; an instance in which a base runner advances safely during the delivery of a pitch (without the help of a hit or walk or passed ball or wild pitch)
	an advantageous purchase

plagiarize (verb)	steal (verb)
take without referencing from someone else's writing or speech; of intellectual property	steal a base
	move stealthily
	take without the owner's consent