Pabbajjā is a word that comes from a religion called Buddhism. It means to become a monk or a nun.
Now, being a monk or a nun means that you have dedicated your life to following the teachings of the Buddha. The Buddha was a wise man who lived a long time ago and taught people about how to be kind and live a good life.
When someone decides to become a monk or a nun, they have to follow certain rules. For example, they have to shave their head and wear simple robes. They also have to live in a temple or monastery and spend a lot of time meditating and studying the Buddhist teachings.
This decision to become a monk or a nun is a big one, and it's not something that everyone does. But for those who feel called to it, it can be a very fulfilling and meaningful way to live their life.