kəˈliptrə noun
( -s )
Etymology: New Latin, from Greek kalyptra veil, from kalyptein
1. : the archegonium of a liverwort or moss when distended and modified by the growth of the enclosed sporophyte ; especially : such an archegonium when forming a thin membranous hood over the capsule of a moss
2. : a caplike covering of a flower or fruit (as the calyx of plants of the genus Eschscholtzia )
3. : root cap