runner

Barback is a synonym of runner.

As nouns the difference between runner and barback

is that runner is agent noun of run; somebody who runs while barback is an assistant to a bartender.

As a verb barback is

to work as a barback.

As nouns the difference between runner and exacta

is that runner is agent noun of run; somebody who runs: while exacta is a bet in which the bettor must correctly pick the two runners who finish first and second, in the correct order.

As nouns the difference between runner and shinsplint

is that runner is agent noun of run; somebody who runs while shinsplint is a painful inflammation of the muscles in the shins; especially frequent in runners, or a general term for a painful condition in the shins.