Babyish
Part of speech: adjective
Definition: Like a baby; childish; puerile; simple.
Immature
Part of speech: adjective
Definition: Not fully formed or developed, unripe.Childish in behavior.
Example sentence: I don't like the word 'experiment' in the context of art in general. It implies something immature, unfinished, something entertaining for a moment before it becomes irrelevant.