The Collaborative International Dictionary of English v.0.48:

Roundhouse \Round"house`\, n.
   1. A constable's prison; a lockup, watch-house, or station
      house. [Obs.]
      [1913 Webster]

   2. (Naut.)
      (a) A cabin or apartament on the after part of the
          quarter-deck, having the poop for its roof; --
          sometimes called the coach.
      (b) A privy near the bow of the vessel.
          [1913 Webster]

   3. A house for locomotive engines, built circularly around a
      turntable.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Coach \Coach\ (k[=o]ch; 224), n. [F. coche, fr. It. cocchio,
   dim. of cocca little boat, fr. L. concha mussel, mussel
   shell, Gr. ?, akin to Skr. [,c]ankha. Cf. Conch,
   Cockboat, Cockle.]
   1. A large, closed, four-wheeled carriage, having doors in
      the sides, and generally a front and back seat inside,
      each for two persons, and an elevated outside seat in
      front for the driver.
      [1913 Webster]

   Note: Coaches have a variety of forms, and differ in respect
         to the number of persons they can carry. Mail coaches
         and tallyho coaches often have three or more seats
         inside, each for two or three persons, and seats
         outside, sometimes for twelve or more.
         [1913 Webster]

   2. A special tutor who assists in preparing a student for
      examination. [Colloq.]
      [1913 Webster]

            Wareham was studying for India with a Wancester
            coach.                                --G. Eliot.
      [1913 Webster]

   3. (Naut.) A cabin on the after part of the quarter-deck,
      usually occupied by the captain. [Written also couch.]
      [Obs.]
      [1913 Webster]

            The commanders came on board and the council sat in
            the coach.                            --Pepys.
      [1913 Webster]

   4. (Railroad) A first-class passenger car, as distinguished
      from a drawing-room car, sleeping car, etc. It is
      sometimes loosely applied to any passenger car.
      [1913 Webster]

   5. One who coaches; specif. (sports), a trainer; one who
      assists in training individual athletes or the members of
      a sports team, or who performs other ancillary functions
      in sports; as, a third base coach.
      [+PJC]

The Collaborative International Dictionary of English v.0.48:

Coach \Coach\, v. t. [imp. & p. p. Coached; p. pr. & vb. n.
   Coaching.]
   1. To convey in a coach. --Pope.
      [1913 Webster]

   2. To prepare for public examination by private instruction;
      to train by special instruction. [Colloq.]
      [1913 Webster]

            I coached him before he got his scholarship. --G.
                                                  Eliot.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Coach \Coach\, v. i.
   To drive or to ride in a coach; -- sometimes used with it.
   [Colloq.] "Coaching it to all quarters." --E. Waterhouse.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Coacher \Coach"er\, n.
   1. A coachman. [Obs.]
      [Webster 1913 Suppl.]

   2. A coach horse.
      [Webster 1913 Suppl.]

   3. One who coaches; specif. (Baseball), one of the side at
      the bat posted near first or third base to direct a base
      runner; also called a coach; as, third base coach.
      [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

coach
    n 1: (sports) someone in charge of training an athlete or a team
         [syn: coach, manager, handler]
    2: a person who gives private instruction (as in singing,
       acting, etc.) [syn: coach, private instructor, tutor]
    3: a railcar where passengers ride [syn: passenger car,
       coach, carriage]
    4: a carriage pulled by four horses with one driver [syn:
       coach, four-in-hand, coach-and-four]
    5: a vehicle carrying many passengers; used for public
       transport; "he always rode the bus to work" [syn: bus,
       autobus, coach, charabanc, double-decker, jitney,
       motorbus, motorcoach, omnibus, passenger vehicle]
    v 1: teach and supervise (someone); act as a trainer or coach
         (to), as in sports; "He is training our Olympic team"; "She
         is coaching the crew" [syn: coach, train]
    2: drive a coach

Moby Thesaurus II by Grady Ward, 1.0:

142 Moby Thesaurus words for "coach":
   Privatdocent, Privatdozent, Pullman, Pullman car, advise, advocate,
   amateur athlete, archer, athlete, athletic coach, baggage car,
   ballplayer, barge, baseballer, baseman, batter, battery,
   blocking back, boat, bowman, boxcar, brief, bus, caboose, car,
   carriage, cart, catcher, center, chair car, coacher, coal car,
   competitor, confer, consult with, counsel, covered waggon, cram,
   cram with facts, crammer, cricketer, day coach, defensive lineman,
   diner, dinghy, dining car, direct, drawing room, dray, drill,
   driller, drillmaster, end, exercise, ferry, flat, flatcar, float,
   footballer, forerunner, games-player, gamester, gondola, groomer,
   guard, guide, infielder, instruct, instructor, jock, jumper,
   kibitz, lighter, lineman, local, luggage van, mail car, mail van,
   meddle, mentor, motor coach, offensive lineman, omnibus, outfield,
   outfielder, palace car, parlor car, passenger car, pathfinder,
   player, poloist, preparationist, preparator, prepare, preparer,
   prescribe, prime, private instructor, professional athlete, prompt,
   propose, pugilist, quarterback, racer, raft, railway car,
   recommend, reefer, refrigerator car, roomette, school, ship,
   skater, sled, sledge, sleeper, smoker, smoking car, sport,
   sportsman, stockcar, stuff with knowledge, submit, suggest, tackle,
   tailback, tank, teacher, tender, toxophilite, trailblazer, train,
   trainer, truck, tutor, tutorer, van, waggon, wagon, wheelbarrow,
   wingback, wrestler



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

COACH
       Component based Open source ArCHitecture for distributed systems
(CORBA)