the GNU version of the Collaborative International Dictionary of English
ad. In an immature manner.
The Century Dictionary and Cyclopedia
In an immature manner; unripely; prematurely; crudely.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
ad. in an immature manner
Word Usage
"Not so easy to behave immaturely when everyone knows your name, is it wilson? the Repugs have hit an all-time low, this after all the hijinks over the summer."