For example, in Australia a bolter is a racehorse that wins at long betting odds.
Most often, bolting refers to a "runaway" - horses that gallop off with a handler at high speed, whether being ridden under saddle or driving in harness.
Less often, bolting is a deliberate disobedience by a horse that wishes to rid itself of a handler or avoid an unpleasant situation.
What a horse actually does is to raise its head and tighten its jaw in a manner that allows it to ignore bit pressure.
Methods to prevent bolting feed involve adding objects such as hay cubes, chopped straw ("chaff") or medium-sized rocks to a feed container to slow the horse's eating.