Wiktionary
gentleman of leisure
n. A gentleman who is of independent means and so does not need employment, one who is free from duties and responsibilities, a dilettante.
Usage examples of "gentleman of leisure".
If so, they were no doubt referencing the scene where the nameless narrator, a demure, bookish gentleman of leisure (a fellow much like James himself, a noted scholar and writer of ghost stories who lived from 1862 to 19361, takes a stroll in order to ponder how he can best protect his five magical jars, delivered to him by a talking brook through the agency of a unique plant which the brook has advised the narrator to swallow whole.