The word 飞碟 (fēi dié), meaning "flying saucer" or "UFO," is a compound noun formed through semantic metaphor. It combines the character 飞 (fēi), meaning "to fly," with 碟 (dié), meaning "plate" or "shallow dish," to create the literal visual concept of a "flying dish." This formation directly translates the Western description of the object's shape, making it a vivid, descriptive calque where both morphemes contribute their core meanings to evoke the iconic image of a disc-shaped object moving through the air.