1. Relating to a nest or a breeding place for a female insect, frog, snake, etc: The nidal home of the spider was complex and made of a tough web to protect its eggs.
2. Pertaining to a special container or nest, in which eggs are laid by female birds and baby offspring develop: The mother chickadee lays very small oval and reproductive objects in a nidal structure, keeps them warm with her body, and some days later they hatch and the baby chickadees are fed and protected by both the mother and father until the little ones can grow and fly away.