yen comes from Cantonese 癮 (yáhn, 'craving, addiction'), originally referring to an opium craving, borrowed into English in the early 20th century. The path is chiefly one of transmission: an older form is taken into English, with the word's shape and meaning carried through the language names and forms preserved in the history. In modern use, the noun sense is "a strong longing or craving for something", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. Its nearest semantic neighbors include craving, longing, hankering, desire, but the etymology gives the word its own historical profile within that field. The principal historical forms in the chain include Cantonese 癮, which anchor the explanation in named linguistic material.