The term 'TAMAGOTCHI, ONCE' is a crossword solution for the three-letter word 'FAD'. A Tamagotchi is a handheld digital pet created in Japan in 1996. It was an extremely popular toy in the late 1990s and early 2000s, and has since become a cultural phenomenon. The name is a combination of the Japanese words for 'EGG' and 'WATCH'. Tamagotchi owners must take care of their virtual pet by feeding it, playing with it, and cleaning up after it.