childishly
🇺🇸
/ˈtʃaɪldɪʃli/
🇬🇧
/ˈtʃaɪldɪʃli/
in a way that is typical of a child
He acted childishly when he didn't get his way.
an adult who behaves in a stupid or silly way
He childishly refused to share his toys with the other children.