1.Father. Depending on the suffix used, the level of politeness will also vary.
2. Is also used by close girl/boy friends of a father's child to show closeness of relationship to the child.
Ojousama is a descriptive term often used in Japanese fiction that translates directly to "young lady".
Typically, however, it is used specifically to describe rich girls.
Ojousamas are also characterized by their behaviour, most commonly being their distinct way of laughing.
Takumi: "Have you seen the new transfer student?"
Kenta: "Yeah, she radiates that ojousama energy."
Takumi: "I know right? You can tell by how she laughs"
Reiko: "*ohohoho*, what do we have here? It looks like I'm famous already~"