Dark Horse (2005 film)
WordNet
noun
(1) A racehorse about which little is known
(2) A political candidate who is not well known but could win unexpectedly
WiktionaryText
Etymology
Originally an allusion to an unknown horse winning a race, as used in an 1831 novel The Young Duke by Benjamin Disraeli.
Noun
- A candidate who is nominated unexpectedly, without previously having been discussed or considered as a likely choice.
- An unexpected success.
- Everyone was expecting the red team to win, but the greens were the dark horse in the event.