The prince started horseback riding.
The Prince's left hand is big.
After the prince kissed the frog, the frog ate the prince.
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.
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.