conoid
a ruled surface, whose rulings (lines) fulfill the additional conditions that ① all rulings are parallel to a plane (the directrix plane) and ② all rulings intersect a fixed line (the axis)
en-US/ˈkoʊnɔɪd/
en-GB/kəʊnɔɪd/
a ruled surface, whose rulings (lines) fulfill the additional conditions that ① all rulings are parallel to a plane (the directrix plane) and ② all rulings intersect a fixed line (the axis)