The Collaborative International Dictionary of English v.0.48:

Halfpace \Half"pace`\ (-p[=a]s`), n. (Arch.)
   A platform of a staircase where the stair turns back in
   exactly the reverse direction of the lower flight. See
   Quarterpace.
   [1913 Webster]

   Note: This term and quarterpace are rare or unknown in the
         United States, platform or landing being used
         instead.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Platform \Plat"form`\, n. [Plat, a. + -form: cf. F. plateforme.]
   1. A plat; a plan; a sketch; a model; a pattern. Used also
      figuratively. [Obs.] --Bacon.
      [1913 Webster]

   2. A place laid out after a model. [Obs.]
      [1913 Webster]

            lf the platform just reflects the order. --Pope.
      [1913 Webster]

   3. Any flat or horizontal surface; especially, one that is
      raised above some particular level, as a framework of
      timber or boards horizontally joined so as to form a roof,
      or a raised floor, or portion of a floor; a landing; a
      dais; a stage, for speakers, performers, or workmen; a
      standing place.
      [1913 Webster]

   4. A declaration of the principles upon which a person, a
      sect, or a party proposes to stand; a declared policy or
      system; as, the Saybrook platform; a political platform.
      "The platform of Geneva." --Hooker.
      [1913 Webster]

   5. (Naut.) A light deck, usually placed in a section of the
      hold or over the floor of the magazine. See Orlop.
      [1913 Webster]

   Platform car, a railway car without permanent raised sides
      or covering; a f?at.

   Platform scale, a weighing machine, with a flat platform on
      which objects are weighed.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Platform \Plat"form`\, v. t.
   1. To place on a platform. [R.]
      [1913 Webster]

   2. To form a plan of; to model; to lay out. [Obs.]
      [1913 Webster]

            Church discipline is platformed in the Bible.
                                                  --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

platform
    n 1: a raised horizontal surface; "the speaker mounted the
         platform"
    2: a document stating the aims and principles of a political
       party; "their candidate simply ignored the party platform";
       "they won the election even though they offered no positive
       program" [syn: platform, political platform, political
       program, program]
    3: the combination of a particular computer and a particular
       operating system
    4: any military structure or vehicle bearing weapons [syn:
       platform, weapons platform]
    5: a woman's shoe with a very high thick sole [syn: chopine,
       platform]

Moby Thesaurus II by Grady Ward, 1.0:

154 Moby Thesaurus words for "platform":
   address, agora, amphitheater, arena, athletic field, auditorium,
   background, balcony, bear garden, bench mark, billiard table,
   bookmark, bowl, bowling green, boxing ring, bull ring, cairn,
   campus, canvas, catafalque, catstone, circus, cockpit, coliseum,
   colosseum, course, creed, dais, dead flat, dead level,
   declaration of policy, deliver an address, discourse, earth,
   emplacement, esplanade, estrade, field, flat, flatland, floor,
   forum, gallery, give a talk, ground, guiding principles, gym,
   gymnasium, hall, heliport, hippodrome, homaloid, horizontal,
   horizontal axis, horizontal fault, horizontal line,
   horizontal parallax, horizontal plane, horizontal projection,
   hustings, issue, keynote address, keynote speech, landing,
   landing pad, landing stage, landmark, launching pad, ledge, level,
   level line, level plane, lighthouse, lightship, line, lists,
   locale, mark, marker, marketplace, mat, mean sea level, menhir,
   milepost, milestone, milieu, monument, open forum, palaestra,
   parade ground, parterre, party line, party platform, pharos, pit,
   place, plain, plan of action, plane, plank, podium, policy, polity,
   position paper, prairie, precinct, principles, prize ring,
   procedure, program, public square, pulpit, purlieu, range, ring,
   rostrum, scene, scene of action, scenery, sea level, sea of grass,
   seamark, setting, site, soapbox, speak, speechify, sphere,
   squared circle, stadium, stage, stage set, stage setting, stand,
   step terrace, steppe, stump, table, take the floor, take the stump,
   talk, tenets, terrace, terrain, theater, tilting ground, tiltyard,
   tower, tribunal, tribune, walk, watchtower, water level,
   wrestling ring



The Free On-line Dictionary of Computing (30 December 2018):

platform

   Specific computer hardware, as in the phrase
   "platform-independent".  It may also refer to a specific
   combination of hardware and operating system and/or
   compiler, as in "this program has been ported to several
   platforms".  It is also used to refer to support software for
   a particular activity, as in "This program provides a platform
   for research into routing protocols".

   (1994-12-07)