yen (n.1)

Japanese monetary unit, 1875, from Japanese yen, from Chinese yuan "round, round object, circle, dollar."

yen (n.2)

"sharp desire, hunger," 1906, earlier yen-yen (1900), yin (1876) "intense craving for opium," from Chinese (Cantonese) yan "craving," or from a Beijing dialect word for "smoke." Reinforced in English by influence of yearn.