The most common and most likely answer to this crossword clue is the 7 letter word PIEBALD
I've seen this crossword clue in Financial Times
P
I
E
B
A
L
D
More clues leading to the result PIEBALD
- Baked dish with no cover on top is unevenly coloured
- Baked dish having smooth skin with patches
- Unevenly coloured baked dish, no cover on top
- Horse that is in lead has new lad on
- Obvious to follow prices given the odds for a horse
- Black and white photo’s source that is obvious
- Horse able to manoeuvre during swim, doing the backstroke?
- Horse that is taken into lead by excited lad
- Unevenly coloured 25 dish: no cover on top?
- Unusual bipedal horse
Buddy explains!

The straight part
We know that "a horse" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a horse = piebald.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PIEBALD mean?
PIEBALD noun- An animal with piebald coloration.
- Spotted or blotched, especially in black and white.
- Of mixed character, heterogeneous.