A zucchetto is essentially a
Catholic yarmulke. It shares a common origin with the modern Jewish yarmulke (a need to keep one's head covered originating in the
Talmud), but evolved in its own right over the past score of centuries into what it is today.
Nowadays, high officials in the Roman Catholic Church wear zucchettos while they're involved with their God-ly duties. The ranks are as follows:
The
patriarchs of the various
Eastern Catholic churches also wear zucchettos.
According to mauler, "zucchetto" literally means "little gourd," and it has the same Latin origin as the word "zucchini." That's just funny.