1. [n]  a journey usually by ship; "the outward passage took 10 days"
2. [n]  a surveying instrument for measuring horizontal and vertical angles, consisting of a small telescope mounted on a tripod
3. [n]  facility consisting of the roads and equipment necessary for the movement of passengers or goods
4. [v]  cause or enable to pass through; "The canal will transit hundreds of ships every day"
5. [v]  revolve (the telescope of a surveying transit) about its horizontal transverse axis in order to reverse its direction
6. [v]  astronomy: pass across (a sign or house of the zodiac) or pass across (the disk of a celestial body or the meridian of a place); "The comet will transit on September 11"
7. [v]  make a transit

1. \Trans"it\, n. [L. transitus, from transire to go over:
   cf. F. transit. See {Transient}.]
   1. The act of passing; passage through or over.
            In France you are now . . . in the transit from one
            form of government to another.        --Burke.
   2. The act or process of causing to pass; conveyance; as, the
      transit of goods through a country.
   3. A line or route of passage or conveyance; as, the
      Nicaragua transit. --E. G. Squier.
   4. (Astron.)
      (a) The passage of a heavenly body over the meridian of a
          place, or through the field of a telescope.
      (b) The passage of a smaller body across the disk of a
          larger, as of Venus across the sun's disk, or of a
          satellite or its shadow across the disk of its
          primary.
   5. An instrument resembling a theodolite, used by surveyors
      and engineers; -- called also {transit compass}, and
      {surveyor's transit}.
   Note: The surveyor's transit differs from the theodolite in
         having the horizontal axis attached directly to the
         telescope which is not mounted in Y's and can be turned
         completely over about the axis.
   {Lower transit} (Astron.), the passage of a heavenly body
      across that part of the meridian which is below the polar
      axis.
   {Surveyor's transit}. See {Transit}, 5, above.
   {Transit circle} (Astron.), a transit instrument with a
      graduated circle attached, used for observing the time of
      transit and the declination at one observation. See
      {Circle}, n., 3.
   {Transit compass}. See {Transit}, 5, above.
   {Transit duty}, a duty paid on goods that pass through a
      country.
   {Transit instrument}. (Astron.)
      (a) A telescope mounted at right angles to a horizontal
          axis, on which it revolves with its line of
          collimation in the plane of the meridian, -- used in
          connection with a clock for observing the time of
          transit of a heavenly body over the meridian of a
          place.
      (b) (Surv.) A surveyor's transit. See {Transit}, 5, above.
   {Transit trade} (Com.), the business conected with the
      passage of goods through a country to their destination.
   {Upper transit} (Astron.), the passage of a heavenly body
      across that part of the meridian which is above the polar
      axis.
   

2. \Trans"it\, v. t. (Astron.)
   To pass over the disk of (a heavenly body).
   

Subsystem of ICES. Sammet 1969, p.616.