0 a person who keeps their interests and ideas secret, especially someone who has a surprising ability or skill:
1 a horse or a politician who wins a race or competition although no one expected them to
2 a person who is not expected to succeed in or unexpectedly wins an election, race, or other competition:
a dark horse in the primaries
It may be that, not for the first time, this dark horse entered at the last moment will win the race.
Trade analysts even called the film as the dark horse of the first quarter of 2008.
He then recounts how once he was suffering from writer's block when a knight on a dark horse appeared, leaning on his spear, and supplied the missing lines for him.
They are the dark horse in the public transport debate.
In common parlance, he is the dark horse; and he, too, ought to be here to answer some of these very pertinent questions.
I am sorry that he is not here, but he is a bit of a dark horse.
This left an opening for a dark horse candidate to emerge.
He caught the attention of party leaders in 1958, and was asked to run for governor as a dark horse candidate.
