Uracil
Part of speech: noun
Definition: one of the bases of RNA which pairs with adenine and is symbolised by U.
U
Part of speech: pronoun
Definition: you
Part of speech: abbreviation
Definition: Underwater.
Part of speech: noun
Definition: The name of the letter UA thing in the shape of the letter U
Part of speech: symbol
Definition: The twenty-third (23rd) letter of the English alphabet.