Childlike, a.
Resembling a child, or that which belongs to children; becoming a child; meek; submissive; dutiful. "Childlike obedience." Hooker.
Note: Childlike, as applied to persons grown up, is commonly in a good sense; as, childlike grace or simplicity; childlike modesty.
Shades of meaning
Fernald has no entry of its own for childlike; he lists it under youthful.
He lists it without comment; the entries above explain its neighbors.