joy: [13] Latin gaudēre meant ‘rejoice’ (it came from a prehistoric base *gāu-, which also produced Greek gēthein ‘rejoice’). From it was derived the noun gaudium ‘joy’, which passed into English via Old French joye. From the same source come English enjoy and rejoice. The use of joystick for the ‘control stick of an aircraft’ (perhaps inspired by an earlier slang sense ‘penis’) dates from around 1910. => enjoy, rejoice[joy etymology, joy origin, 英语词源]