Ü definition

(1) (chiefly British) of or appropriate to the upper classes especially in language use

(2) The 21st letter of the Roman alphabet

(3) A heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons

(4) A base containing nitrogen that is found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine