What could it mean?
A horse in a dream is almost always about power that is not yours alone. Were you on it, or looking at it?
— Vera
Horses are one of the oldest animals in recorded dreams, and unlike most animals they arrive with a relationship built in: something strong that can be worked with but not commanded. That is why the position matters so much — on its back, holding the reins, or standing in a field watching.
The usual reading is strength and drive: energy the dreamer has, or wants, or is trying to steer. Being thrown, or failing to catch one, tends to attach to something that will not be forced.
Across cultures the horse carries freedom, status and journey at once. A white horse in particular has picked up so much meaning over the centuries that it is worth asking whether the colour meant anything to you at the time.
Traditions that treat the horse as a carrier read it as what takes you somewhere you could not walk to. The attention goes to whether the two of you agreed on the direction.
Your dream is more than one symbol.
Riding well is not the same dream as a horse that would not be caught. Tell Vera how it went.
Interpret my dream →What does riding a horse mean in a dream?
Riding is generally connected to working with something powerful rather than controlling it. Dreamers usually remember whether they were confident or holding on.
What does a white horse mean?
It carries centuries of symbolism — purity, victory, sometimes death — which is a lot for one colour to hold. What it meant to you in the dream is a better guide than the list.
What does it mean if the horse was frightened or hurt?
An animal in distress tends to attach to something the dreamer feels responsible for. It is one of the images people report waking up still thinking about.
What if I could not catch it?
Chasing an animal that will not be caught is a common variant. People usually connect it to something that only comes on its own terms.
Do horses in dreams mean the same thing for riders?
Not usually. For someone who rides, a horse dream is often partly a memory, and the ordinary detail of the yard has to be separated out first.