bill vs rob

bill is a noun but rob is not a noun.

Word	Noun	Adjective	Verb	Adverb
bill	Yes	No	Yes	No
rob	No	No	Yes	No

bill (noun)	rob (noun)
the entertainment offered at a public presentation
horny projecting mouth of a bird
a brim that projects to the front to shade the eyes
a cutting tool with a sharp edge
a sign posted in a public place as an advertisement
an itemized statement of money owed for goods shipped or services rendered
an advertisement (usually printed on a page or in a leaflet) intended for wide distribution
a statute in draft before it becomes law
a list of particulars (as a playbill or bill of fare)
a piece of paper money (especially one issued by a central bank)

bill (verb)	rob (verb)
advertise especially by posters or placards	take something away by force or without the consent of the owner
publicize or announce by placards	rip off; ask an unreasonable price
demand payment