u
1. [ [Undefined_variable] ] pronoun, second person singular
Synonyms: you thee ye thou
2. [ adjective ] (chiefly British) of or appropriate to the upper classes especially in language use
Related terms: UK upper-class
3. [ noun ] (biology,chemistry,biochemistry) a nitrogen-containing base found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine
Synonyms: uracil
Related terms: base pyrimidine nucleotide ribonucleic_acid
4. [ noun ] the 21st letter of the Roman alphabet
Related terms: letter Roman_alphabet
5. [ noun ] (chemistry,physics) a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons
Synonyms: atomic_number_92 uranium
Related terms: metallic_element uranium_235 uranium_238 uraninite
Similar spelling:   Uy