A groom in waiting is someone who is waiting to get married. Imagine you have a toy car and you're waiting your turn to play with it. The groom in waiting is waiting for his turn to get married.
He's like a prince waiting for his princess to arrive at the ball. As soon as she arrives, they will get married!
The groom in waiting is excited and happy, but also a little nervous. He wants everything to be perfect for his big day.
He may have to wait a little while before he gets married because there are lots of things that need to be done first. His family and friends will help him get ready for his wedding day. They will make sure he looks handsome and help him prepare for the big ceremony.
Overall, a groom in waiting is someone who is eagerly waiting for his turn to get married, and he is busy preparing and getting ready for his special day.