Immature
Part of speech: adjective
Definition: Not fully formed or developed, unripe. Childish in behavior.
Example sentence: Once in a while, I do these things that would make the 10-year old version of me laugh. I don't know why. You've got to do something a little bit immature. I'm surprised at how often those are my best ideas.
Unfeathered
Part of speech: adjective
Definition: Lacking feathers