Meanings (ES + gloss)
parábola
The conic section formed by the intersection of a cone with a plane parallel to a tangent plane to the cone; the locus of points equidistant from a fixed point (the focus) and line (the directrix).
And it saves his life. As he's buzzing down a curving, narrow canal, a narrow green parabola appears hanging across the water in front of him, suddenly rising out of the water and…