A natural structure having the form of a pin. A pinnacle, point, or apex; the peak of a mountain. Now Irish English.

The highest part of something, esp. when forming a point; the tip, top, or peak; a pointed extremity.

The highest point, the apex (literal and figurative); a high projecting point or tip. Obsolete. rare.

transferred. An apex or vertex, as of a cone or pyramid; a point at which lines converge. Obsolete.

= cusp, n., in various senses.

gen. A point, pointed end, apex, peak; an ornament of a pointed form.

figurative. A highest point, summit, or zenith of achievement, success, development, etc.; a climax, an acme. In later use: esp. a point (in time)…