Someone who is expected to win. The term comes from horse racing and began to be used figuratively in the first half of the 1900s. Its most prominent context is political, referring to a candidate who leads his or her opponents in an election, but it also occurs in other kinds of contest. Thus Wilbur Smith used it in Gold Mine (1970): “He had joined C.R.C. a mere twelve years previously and now he was the front runner.”