公主 is read as こうしゅ (koushu) and means princess.
こうしゅ
koushu
こうしきしゅぎ
formalism
しゅじんこう
head (of a household)
くげ
Imperial Court
こうかい
opening to the public
こうめい
Komeito (Japanese political party)
こうりつ
public (institution)
こうせい
justice
こうげん
declaration
こうし
envoy
こうあん
public safety
こうしゃ
public corporation
おおやけ
public (use, matter, forum, etc.)