Definitions
1.NounA wheeled vehicle, generally pulled by a horse.
2.NounA passenger car, either drawn by a locomotive or part of a multiple unit.
3.NounA trainer or instructor."football coach; spelling coach; public coach; horseriding coach; politics coach"
4.NounA long-distance, or privately hired, bus.
5.NounThe forward part of the cabin space under the poop deck of a sailing ship; the fore-cabin under the quarter deck.
6.NounThe part of a commercial passenger airplane or train reserved for those paying the lower standard fares; the economy section."We couldn't afford the good tickets, so we spent the flight crammed in coach."
7.NounThe lower-fare service whose passengers sit in this part of the airplane or train; economy class.
8.VerbTo train.
9.VerbTo instruct; to train."She has coached many opera stars."
10.VerbTo study under a tutor.
11.VerbTo travel in a coach (sometimes coach it).
12.VerbTo convey in a coach.
13.AdverbVia the part of a commercial passenger airplane or train reserved for those paying the lower standard fares; via the economy section."John flew coach to Vienna, but first-class back home."
14.Adverb↑ Douglas Harper (2001–2026), “coach”, in Online Etymology Dictionary.