• twenty-first letter of the Latin alphabet, fifth and final vowel
  • phonetic name: "near-close near-back vowel" or "close central rounded vowel; sound: press your tongue to your palate and vocalize while closing your lips
  • Egyptian hieroglyphs was a snake/dragon (Cerastes)
  • Proto-Sinaitic letter for U, V & W was waw, all derived from the letter F
  • Greeks adopted it as their letter upsilon (uppercase Υ, lowercase υ), pronounced yoo-psil-on, and meaning "naked U"
  • in Roman, 'U' (written V) represents 5; on monuments, U was often an abbreviation of urbs (city), usus (used/usage) or uxor (woman)
  • U and V were indistinguishable for centuries; in the ninth century, we see U sometimes topped with a small accent / diacritic mark
  • the first time the letters U and V were consistently differentiated was in 1386; in 1548, U was first used as a vowel (with a rounded base) and V as a consonant (with a pointed base), but this was not officially recognized by the French Academy until 1726
  • W, aka "double-U", was originally called "double vay" / "double-V" (which actually makes more sense) :P
  • upper case U came into being in 1629
  • U is the only vowel that doesn't have a consistent matching long vowel sound (vs. ay, ee, igh, oh); long U can also be pronounced "oo" (ie. blue, rude)
  • short U can be shallow (ie. cup, sun, butter) or deep (ie. push, pull)
  • U is very common in vowel pairings, which produces a huge variety of sounds (au, ua, eu, ue, iu, ui, ou, uo and uu)
  • U almost always follows Q (exceptions here), and very often after G
  • associated with receptacle, earth, femininity
  • U evokes a cup or container designed to receive, hold or contain; often related to the female uterus (n.b.: U also appears twice in the word uterus)
  • U also suggests a horseshoe or magnet - strong, potent, made or iron
  • U is associated with the colour green, flora and chlorophyll, and sometimes connected to wood, the rustic and traditional values
  • when sung on musical note C, U acts on the first chakra (aka "the root chakra"), which is associated with the colour red, squares, and the universe
  • U is often used to describe the shape of objects: U-lock, U-turn, U-bolt, U-rail, U-tube
  • U-boat is a military submarine from the German Unterseeboot, meaning "undersea boat"
  • U inside a circle, Ⓤ, indicates kosher, which means "suitable for consumption" in Hebrew
  • U in education can mean Unsatisfactory
  • U abbreviates University (U of T = University of Toronto) and United (USA, UAE, etc.)
  • UV abbreviates ultra-violet
  • phonetic sound, "yoo", is the second-person personal pronoun (you!), or a female domestic sheep (ewe)
  • yu (竽; pronounced yoo) is also a free reed wind instrument imported from ancient China
  • U very often abbreviates the word "you", especially in text messaging, email, and SMS language
  • rockband U2 chose their name partly in reference to an Irish federal unemployment insurance form called a U-2
  • U is the chemical symbol for uranium (#92 on the periodic table), a silvery-white metal that is the only naturally occurring fissile isotope. Its radioactive properties make it practical for medical x-rays, nuclear power and nuclear weapons.
  • NATO phonetic alphabet: UNIFORM
  • "From a lump of clay we fashion a vase; This empty space in the vase permits its use." - Lao Tsu
  • "U, waves, divine vibrations of verdant seas, Peace of pastures dotted with livestock, peace of the furrows, Which alchemy prints on broad studious brows." - Arthur Rimbaud, Vowels
  • "'U' is the urn." -Victor Hugo, French poet & playwright
  • "The sound vibration of the vowel 'U' means 'to carry, carrying light'." - Joseph E. Rael
  • U can also abbreviate union, united, upper class, upper case, Uruguay