trademark vs Yahoo!

trademark and Yahoo! both are nouns.

Word	Noun	Adjective	Verb	Adverb
trademark	Yes	No	Yes	No
Yahoo!	Yes	No	No	No

trademark (noun)	Yahoo! (noun)
a distinctive characteristic or attribute of someone or something	a widely used search engine for the web that finds information, news, images, products, finance
a formally registered symbol identifying the manufacturer or distributor of a product

trademark (verb)	Yahoo! (verb)
register the trademark of
mark with a brand or trademark