̷ ̷ˈ ̷ ̷rēəm noun
( plural delthy·ria -rēə)
Etymology: New Latin, probably irregular from Greek dēlos clear, visible, evident + thyrion little door, diminutive of thyra door — more at adel- , door
: the opening between the beak and the hinge through which the pedicle of certain brachiopods extends