喔

ō ㄛ

- oh I see (used to indicate realization, understanding)
  interjection

o ˙ㄛ

- (sentence-final particle) (used to convey a friendly tone when giving an admonition or correcting sb etc)
  Tw

wō ㄨㄛ

- cry of a rooster (usu. reduplicated)
  onom.

Sources