means The point where two or more lines, edges, or surfaces meet — the highest point or the sharp corner of a shape, angle, or curve.

from From Latin vertex, meaning 'whirl, top, highest point' — literally the crown of the head where the hair spirals into a whorl. It grew from the verb vertere, 'to turn' (the same root that gives us 'convert,' 'reverse,' and 'vortex,' its swirling sibling). The Romans saw the top of anything as the place where it turned — the pole of the sky, the summit of a mountain, the spinning point of a crown. Geometry later borrowed it for the precise point where lines turn to meet.