the GNU version of the Collaborative International Dictionary of English
adj. fully developed; adult; mature; -- of people and animals.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a fully developed person from maturity onward
adj. (of animals) fully developed
Word Usage
"John Edwards today said that after watching his rivals slug it out last night, he's proud to represent what he's calling the grownup wing of the Democratic Party."