Zucchetto

The zucchetto (/(t)suːˈkɛtoʊ, zuːˈ-/, also UK: /tsʊˈ-/, US: /zʊˈ-/, Italian: [dzukˈketto]; meaning 'small gourd', from zucca 'pumpkin'; plural in English: zucchettos) or solideo, officially a pileolus, is a small, hemispherical, form-fitting ecclesiastical skullcap worn by clerics of various Catholic Churches, the Syriac Orthodox Church, and by senior clergy in Anglicanism.

It is also called a pilus, pilos, pileus, pileolo, subbiretum, submitrale, soli deo, berrettino, calotte or calotta.