资料来源 : Webster's Revised Unabridged Dictionary (1913)

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.

   {Direct action}. (Mach.) See {Direct-acting}.

   {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, 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.

资料来源 : WordNet®

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