u

Meanings

• a base containing nitrogen that is found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine
• a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons
• the 21st letter of the Roman alphabet
• (chiefly British) of or appropriate to the upper classes especially in language use

Synonyms

• uracil
• U
• uranium
• atomic number 92

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