VERT'ICAL, a. [L. vertex.]

1. Placed or being in the zenith, or perpendicularly over the head. The sun is vertical to the inhabitants within the tropics at certain times every year.

2. Being in a position perpendicular to the plane of the horizon.

Vertical leaves, in botany, are such as stand so erect, that neither of the surfaces can be called the upper or under.

Vertical anthers, are such as terminate the filaments, and being inserted by their base, stand no less upright than the filaments themselves.

Vertical circle, in astronomy, a great circle passing through the zenith and the nadir. The meridian of any place is a vertical circle. The vertical circles are called azimuths.

Vertical line, in conics, is a right line drawn on the vertical plane, and passing through the vertex of the cone.

Vertical plane, in conics, is a plane passing through the vertex of a cone, and through its axis.

Prime vertical, a great circle of the sphere, perpendicular to the horizon, and passing through the zenith and the east and west points.