It looks like an adjective to me.
(Cross-post.)
Absolutely! Those poor folks at Bing don't know squat about parallel construction.What is odd is that among a bunch of nouns(Images Videos Dict Maps), it stands alone as an adjective. And it seems you can't find a noun instead to make it harmonious with others.
If you have a question about the English language and would like to ask one of our many English teachers and language experts, please click the button below to let us know: