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

synonym: uracil.

Polish: uracyl

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

synonyms: atomic number 92, uranium.

Dutch: uraan, uranium
Polish: U, uran

The 21st letter of the Roman alphabet.

chiefly British Of or appropriate to the upper classes especially in language use.