Bountiful means abundant or given generously. We celebrate the idea of a bountiful harvest with a Thanksgiving cornucopia overflowing with its bounty of pumpkins, apples, squashes, and cranberries.
Bountiful can also mean generously given, with the idea that the original bounty of a harvest came from the gods you prayed to for rain and sun. When you received their gifts, you thanked them for their generosity. Now, bountiful giving is something you might experience with your parents or grandparents, happy just to see you smile on your birthday.