The Collaborative International Dictionary of English v.0.48:
Gentlefolk \Gen"tle*folk`\, Gentlefolks \Gen"tle*folks`\, n. pl. Persons of gentle or good family and breeding. [Generally in the United States in the plural form.] --Shak. [1913 Webster]WordNet (r) 3.0 (2006):
gentlefolk n 1: people of good family and breeding and high social status