The word "天方夜谭" is formed by combining "天方", an archaic Chinese term for Arabia derived from "天方国", with "夜谭", meaning "night talks" or "nocturnal stories", directly referencing the collection of tales known as "One Thousand and One Nights". It literally denotes the Arabian nighttime storytelling tradition, and in modern usage, it functions as an idiom for fantastical or unbelievable narratives.