O (2)

O (ō), n.; pl. O's or Oes (ōz). 1. 1. The letter O, or its sound. “Mouthing out his hollow oes and aes.” Tennyson.
2. 2. Something shaped like the letter O; a circle or oval. “This wooden O ”. Shak.
3. 3. A cipher; zero.
Thou art an O without a figure. Shak.