1. Is the fifteenth letter and the fourth vowel of the English alphabet. It has three distinct vocal sounds-long, as in note or moan: short, as in lot, plot, or dove; and diphthongal, like oo, as in move, prove, &c. It is also the sign of the vocative case, and is sometimes used as an interjection or exclamation. As a prefix to Irish names it signifies son of.

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

• oa,
• oe,
• oh,
• l',
• p',
• 0',
• 9',
• io',
• oi',
• ok',
• lo',
• ol',
• po',
• op',
• 0o',
• o0',
• 9o',
• o9',
• ',
• 'o

The adjective form of "o'" is "own".