Prince
noun, suffix
A king kid is the prince. Someday he'll be the 王, if he's lucky, but right now he's just the king's child.
おうじ
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. Also take note that the reading for 子 (し) is changed to じ.
王子は、じょうばをはじめました。
The prince started horseback riding.
あの王子の左手は大きい。
The Prince's left hand is big.
王子がかえるにキスをすると、そのかえるは王子をたべてしまった。
After the prince kissed the frog, the frog ate the prince.