the GNU version of the Collaborative International Dictionary of English
noun.
A square cap worn by ecclesiastics of the Roman Catholic Church. A cardinal's berretta is scarlet; that worn by other clerics is black, except that a bishop's is lined with green.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
a stiff cap with ridges across the crown; worn by Roman Catholic clergy
Word Usage
"In his homily before he bestowed each new cardinal with the red hat of their office, known as a berretta, Benedict told them their role was "not to be served, but to serve" and urged them to shun "the logic of power.""