What is "direct fire"

Direct \Di*rect"\, a. [L. directus, p. p. of dirigere to direct: cf. F. direct. See Dress, and cf. Dirge.]

1. Straight; not crooked, oblique, or circuitous; leading by the short or shortest way to a point or end; as, a direct line; direct means.

   What is direct to, what slides by, the question.
   --Locke.

2. Straightforward; not of crooked ways, or swerving from truth and openness; sincere; outspoken.

   Be even and direct with me.
   --Shak.

3. Immediate; express; plain; unambiguous.

   He nowhere, that I know, says it in direct words.
   --Locke.

   A direct and avowed interference with elections.
   --Hallam.

4. In the line of descent; not collateral; as, a descendant in the direct line.

5. (Astron.) In the direction of the general planetary motion, or from west to east; in the order of the signs; not retrograde; -- said of the motion of a celestial body.

6. (Political Science) Pertaining to, or effected immediately by, action of the people through their votes instead of through one or more representatives or delegates; as, direct nomination, direct legislation. Direct action.

   1. (Mach.) See Direct-acting.

   2. (Trade unions) See Syndicalism, below. [Webster 1913 Suppl.]

      Direct discourse (Gram.), the language of any one quoted without change in its form; as, he said ``I can not come;'' -- correlative to indirect discourse, in which there is change of form; as, he said that he could not come. They are often called respectively by their Latin names, oratio directa, and oratio obliqua.

      Direct evidence (Law), evidence which is positive or not inferential; -- opposed to circumstantial evidence, or indirect evidence. -- This distinction, however, is merely formal, since there is no direct evidence that is not circumstantial, or dependent on circumstances for its credibility.
      --Wharton.

      Direct examination (Law), the first examination of a witness in the orderly course, upon the merits.
      --Abbott.

      Direct fire (Mil.), fire, the direction of which is perpendicular to the line of troops or to the parapet aimed at.

      Direct process (Metal.), one which yields metal in working condition by a single process from the ore.
      --Knight.

      Direct tax, a tax assessed directly on lands, etc., and polls, distinguished from taxes on merchandise, or customs, and from excise.

n. fire delivered on a target that is visible to the person aiming it

Direct fire refers to the launching of a projectile directly at a target within the line-of-sight of the firer. The firing weapon must have a sighting device and an unobstructed view to the target, which means no objects or friendly units can be between it and the target. A weapon engaged in direct fire exposes itself to return fire from the target. This is in contrast to indirect fire, which refers to firing a projectile on a ballistic trajectory or delivering munitions by guided or unguided missiles. Indirect fire does not need a direct line of sight to the target because the shots are normally directed by a forward observer. As such, indirect fire weapons can shoot over obstacles or friendly units and the weapons can be concealed from counter-battery fire.