a man who saunters around observing society.
French, from flâner ‘saunter, lounge’.
Flâneur is a French noun referring to a person, literally meaning 'stroller', 'lounger', 'saunterer', or 'loafer', but with some nuanced additional meanings. Flânerie is the act of strolling, with all of its accompanying associations. A near-synonym of the noun is boulevardier.