Ver·ti·cal a.
 1. Of or pertaining to the vertex; situated at the vertex, or highest point; directly overhead, or in the zenith; perpendicularly above one.
    Charity . . . is the vertical top of all religion.   --Jer. Taylor.
 2. Perpendicular to the plane of the horizon; upright; plumb; as, a vertical line.
 Vertical angle Astron. & Geod., an angle measured on a vertical circle, called an angle of elevation, or altitude, when reckoned from the horizon upward, and of depression when downward below the horizon.
 Vertical anthers Bot., such anthers as stand erect at the top of the filaments.
 Vertical circle Astron., an azimuth circle.  See under Azimuth.
 Vertical drill, an upright drill.  See under Upright.
 Vertical fire Mil., the fire, as of mortars, at high angles of elevation.
 Vertical leaves Bot., leaves which present their edges to the earth and the sky, and their faces to the horizon, as in the Australian species of Eucalyptus.
 Vertical limb, a graduated arc attached to an instrument, as a theodolite, for measuring vertical angles.
 Vertical line. (a) Dialing A line perpendicular to the horizon. (b) Conic Sections A right line drawn on the vertical plane, and passing through the vertex of the cone. (c) Surv. The direction of a plumb line; a line normal to the surface of still water. (d) Geom., Drawing, etc. A line parallel to the sides of a page or sheet, in distinction from a horizontal line parallel to the top or bottom.
 Vertical plane. (a) Conic Sections A plane passing through the vertex of a cone, and through its axis. (b) Projections Any plane which passes through a vertical line. (c) Persp. The plane passing through the point of sight, and perpendicular to the ground plane, and also to the picture.
 Vertical sash, a sash sliding up and down.   Cf. French sash, under 3d Sash.
 Vertical steam engine, a steam engine having the crank shaft vertically above or below a vertical cylinder.


 Drill, n.
 1. An instrument with an edged or pointed end used for making holes in hard substances; strictly, a tool that cuts with its end, by revolving, as in drilling metals, or by a succession of blows, as in drilling stone; also, a drill press.
 2. Mil. The act or exercise of training soldiers in the military art, as in the manual of arms, in the execution of evolutions, and the like; hence, diligent and strict instruction and exercise in the rudiments and methods of any business; a kind or method of military exercises; as, infantry drill; battalion drill; artillery drill.
 3. Any exercise, physical or mental, enforced with regularity and by constant repetition; as, a severe drill in Latin grammar.
 4. Zool. A marine gastropod, of several species, which kills oysters and other bivalves by drilling holes through the shell. The most destructive kind is Urosalpinx cinerea.
 Bow drill, Breast drill. See under Bow, Breast.
 Cotter drill, or Traverse drill, a machine tool for drilling slots.
 Diamond drill. See under Diamond.
 Drill jig. See under Jig.
 Drill pin, the pin in a lock which enters the hollow stem of the key.
 Drill sergeant Mil., a noncommissioned officer whose office it is to instruct soldiers as to their duties, and to train them to military exercises and evolutions.
 Vertical drill, a drill press.