Adjective u has 1 sense
- u - (chiefly British) of or appropriate to the upper classes especially in language use
Antonyms: lower-class, low-class (indirect, via middle-class, upper-class)
Antonym: middle-class (indirect, via upper-class, lower-class)
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Noun u has 3 senses
- uracil, U - a nitrogen-containing base found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine
--1 is a kind of nucleotide
--1 is a substance of ribonucleic acid, RNA
- uranium, U, atomic number 92 - a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons
--2 is a kind of metallic element, metal
--2 is a substance of uraninite, pitchblende
--2 has particulars: uranium 235; uranium 238
- U - the 21st letter of the Roman alphabet
--3 is a kind of letter, letter of the alphabet, alphabetic character
--3 is a member of Roman alphabet, Latin alphabet
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