Equatorial

equatorial
    adj 1: of or relating to or at an equator; "equatorial diameter"
    2: of or relating to conditions at the geographical equator;
       "equatorial heat"
    3: of or existing at or near the geographic equator; "equatorial
       Africa" [ant: {polar}]
    n 1: a telescope whose mounting has only two axes of motion, one
         parallel to the Earth's axis and the other one at right
         angles to it
    

Equatorial \E`qua*to"ri*al\, a. [Cf. F. ['e]quatorial.]
   Of or pertaining to the equator; as, equatorial climates;
   also, pertaining to an equatorial instrument.
   [1913 Webster]
    

Equatorial \E`qua*to"ri*al\, n. (Astron.)
   An instrument consisting of a telescope so mounted as to have
   two axes of motion at right angles to each other, one of them
   parallel to the axis of the earth, and each carrying a
   graduated circle, the one for measuring declination, and the
   other right ascension, or the hour angle, so that the
   telescope may be directed, even in the daytime, to any star
   or other object whose right ascension and declination are
   known. The motion in right ascension is sometimes
   communicated by clockwork, so as to keep the object
   constantly in the field of the telescope. Called also an
   {equatorial telescope}.
   [1913 Webster]

   Note: The term equatorial, or equatorial instrument, is
         sometimes applied to any astronomical instrument which
         has its principal axis of rotation parallel to the axis
         of the earth.
         [1913 Webster]
    

49 Moby Thesaurus words for "equatorial":
      aestival, amidships, average, blood-hot, blood-warm, calid,
      central, core, equidistant, genial, halfway, interior,
      intermediary, intermediate, luke, lukewarm, mean, medial, median,
      mediocre, mediterranean, medium, mesial, mezzo, mid, middle,
      middlemost, middling, midland, midmost, midships, midway, mild,
      nuclear, room-temperature, subtropical, summery, sunny, sunshiny,
      temperate, tepid, thermal, thermic, toasty, tropical, unfrozen,
      warm, warm as toast, warmish