Quick definitions from WordNet (rootbound)
▸ adjective: having the roots matted or densely tangled ("Shaggy untended lawns of old trees and rootbound scented flowers and shrubs- William Faulkner")
▸ adjective: of a potted plant; grown too large for its container resulting in matting or tangling of the roots
▸ adjective: having the roots matted or densely tangled ("Shaggy untended lawns of old trees and rootbound scented flowers and shrubs- William Faulkner")
▸ adjective: of a potted plant; grown too large for its container resulting in matting or tangling of the roots