The 21st letter of the English alphabet, a vowel,
found in words such as Utopia, United, Ubiquity, or Unstoppable.*Internal
energy: The total kinetic and potential energy associated with the motions and
relative positions of the molecules of an object, excluding the kinetic or
potential energy of the object as a whole. An increase in internal energy
results in a rise in temperature or a change in phase.*A
Burmese title of respect applicable to a man: used before the proper name.*Uranium:
a white, lustrous, radioactive, metallic element, occurring in pitchblende, and
having compounds that are used in photography and in coloring glass. The 235
isotope is used in atomic and hydrogen bombs and as a fuel in nuclear reactors.
Symbol: U; atomic weight: 238.03; atomic number: 92; specific gravity: 19.07.*The
21st in a series.*British.
a designation for motion pictures determined as being acceptable for viewing by
all age groups. But also: A grade that indicates an unsatisfactory status.*A
base containing nitrogen that is found in RNA (but not in DNA) and derived from
pyrimidine; pairs with adenine.*A
turn, in the shape of the letter U, made by a motorist etc in order to reverse
his direction.*Any
spoken sound represented by the letter U or u, as in music, rule, curious, put,
or utopia.