u

Adjective

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

Noun

• the 21st letter of the Roman alphabet

• a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons

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

Related words

• Synonyms: 
  U , uranium , atomic number 92 , uracil