Is honesty a compound noun

No, the noun 'honesty' is not a compound noun. The noun honesty is a common, uncountable, abstract noun; a Word for a quality or condition of truthfulness, integrity, sincerity.

A compound noun is a noun made up of two or more Words merged into one Word with a meaning of its own. There are three types of compound nouns:

open spaced: tennis shoe, front door, paint brush

hyphenated: mother-in-law, fifty-five, six-pack

closed: bathtub, Baseball, houseboat, dishwasher