The term gypsy refers to a nomadic group of Humans from middle Eurasia on Earth.
Within Sherlock Holmes Program 3A, Inspector Lestrade informed Data, who was playing Sherlock Holmes, that a man had been pickpocketed by gypsies. (TNG: "Elementary, Dear Data")
During a date with Christy Henshaw, Geordi La Forge called up a gypsy violinist to play for her. (TNG: "Booby Trap")