What does "front runner" mean?

Any of the most likely winners in a contest, election, etc.

What is a synonym for "front runner"?

Common synonyms include: advance guard, airhead, ancestor, announcer, antecedent, avant garde.

noun

noun ·Rare ·Advanced level

Noun

1
Any of the most likely winners in a contest, election, etc. idiomatic
"[T]he American League pennant did not shape up as much of a race. There were the Indians and the Yankees, front runners as usual."
2
One who engages in front running.

"[T]he American League pennant did not shape up as much of a race. There were the Indians and the Yankees, front runners as usual."