means A symmetrical U-shaped curve formed by slicing a cone parallel to its side, and the path traced by anything thrown under gravity.

from From Greek 'parabolē,' a 'placing beside' or 'comparison' (para-, 'beside,' plus ballein, 'to throw'). The geometer Apollonius of Perga gave it this name from how the curve relates to a fixed line — and the same Greek word, traveling a different road, also gave us 'parable,' that other thing thrown alongside to illuminate by comparison.