kəˈliptə(r), ˈkalə̇p- noun
( plural ca·lyp·ters -ə(r)z ; or cal·yp·te·res ˌkalə̇pˈti(ə)(ˌ)rēz)
Etymology: New Latin, from Greek kalyptēr sheath, from kalyptein to cover, conceal — more at hell
1. : the alula of a two-winged fly especially when large enough to cover the halter
2. : calyptra