Chapter Clubbist to Coach of C by Webster's Dictionary (1913 Edition)

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

The commanders came on board and the council sat in the coach.
Pepys.

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.

Coach
(Coach), v. t. [imp. & p. p. Coached ; p. pr. & vb. n. Coaching.]

1. To convey in a coach. Pope.

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

I coached him before he got his scholarship.
G. Eliot.

Coach
(Coach), v. i. To drive or to ride in a coach; — sometimes used with it. [Colloq.] "Coaching it to all quarters." E. Waterhouse.