courtesy (adjective) courtesy title (noun)

Is courtesy a noun verb or adjective?

noun, plural cour·te·sies. excellence of manners or social conduct; polite behavior. a courteous, respectful, or considerate act or expression.

What kind of word is courtesy?

noun, plural cour·te·sies. excellence of manners or social conduct; polite behavior. a courteous, respectful, or considerate act or expression. indulgence, consent, or acquiescence: a “colonel” by courtesy rather than by right.