Dark Horse 1. a competitor in a race or contest about whom little is known; an unknown 2. a person who reveals little about himself or herself or his or her activities, esp one who has unexpected talents or abilities Hallie Dixon. A dark horse. A snake in the grass. An unsuspected savior. A torment of love. The 23 year old will be on a journey of morals, love, selflessness and selfishness to find out what she was meant to do and who she was meant to be. Unfortunately timing isn't always perfect, but sometimes it does the job.