E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Coach (A).
A private tutor. The term is a pun on getting on fast. To get on fast you take a coach, you cannot get on fast without a private tutor—ergo, a private tutor is the coach you take in order that you may get on quickly. (University slang.)
1
“The books … are expensive, and often a further expense is entailed by the necessity of securing ‘a coach.’”—Stedman Oxford, chap. x. p. 188.
To dine in the coach. In the captain’s private room. The coach or couch of a ship is a small apartment near the stern, the floor being formed of the aftmost part of the quarter-deck, and the roof by the poop.
2
A slow coach. A dull, unprogressive person, somewhat fossilised.
3
“What a dull, old-fashioned chap thou best but thou wert always a slow-coach.”—Mrs. Gaskell: Cibbie Marsh (Era 2).
