1. Is the fifth vowel and the twenty-first letter of the English Alphabet. It has four distinct vocal sounds; the first is short and acute, as in hut; the second a little longer, as in truth; the third long and close, as in mute; and the fourth short and obscure, as in fur, ful, &c. In many words it takes the sound of yu, as in unison; and sometimes of 00, as rule.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• uu,
• fu,
• yu,
• su,
• uy,
• ue,
• tu,
• ju,
• ug,
• bu,
• ou,
• ud,
• iu,
• ul,
• uw,
• uc,
• uo,
• hu,
• ub,
• u

• UY.

The adjective form of the word "U" would be "U-shaped".