runner

runner /ˈrʌnɚ/ noun
plural runners
runner
/ˈrʌnɚ/
noun
plural runners
Britannica Dictionary definition of RUNNER
[count]
1 
a  : a person who runs as part of a sport, for exercise, or in a race
b  : an animal (such as a horse) that runs in a race
2 
a  : a person who delivers messages, reports, materials, or products either within a business or organization or to outside locations : messenger
b  : a person who brings drugs, guns, etc., to a place illegally and secretly
3 
baseball : a player who is on base or is trying to reach a base : base runner
4 
: a long, thin piece or part on which something (such as a sled, skate, or drawer) slides
5 
: a stem of a plant that grows along the ground and that forms new plants
6 
a  : a long, narrow carpet for a hall or staircase
b  : a narrow cloth cover for a table or other piece of furniture

do a runner

British, informal
: to leave a place quickly by running especially to avoid paying a bill or to escape punishment