someone who imports or exports without paying duties
"The customs officer arrested the runner caught smuggling electronics across the border without declaring them."
someone who travels on foot by running
"The long-distance runner completed her marathon in under three hours."
a person who is employed to deliver messages or documents
"he sent a runner over with the contract"
a baseball player on the team at bat who is on base (or attempting to reach a base)
"The runner sprinted toward second base after hitting the ball into the outfield."
a trained athlete who competes in foot races
"The runner crossed the finish line just ahead of his competitors after training all summer."
(football) the player who is carrying (and trying to advance) the ball on an offensive play
"The runner broke through the defensive line and scored a touchdown."
a long narrow carpet
"They bought a stylish runner to place down the center of their hallway."
device consisting of the parts on which something can slide along
"The heavy filing cabinet moves smoothly across the floor because it is equipped with a durable metal runner at its base."
fish of western Atlantic: Cape Cod to Brazil
"The biologist tracked the migration of a runner from New England down to the warm waters off Brazil."
Agent noun of run; one who runs.
"The champion runner finished the marathon in under two hours."
A person who moves, on foot, at a fast pace, especially an athlete.
"The track runner sprinted past the finish line in record time."
In plain English: A runner is someone who runs fast, often as part of a race or sport.
"My dog loves to chase any animal that runs past him in the park."
Usage: In sports contexts, use runner to describe the specific role in relay races where athletes carry and pass batons while sprinting. Avoid confusing this with general terms for anyone jogging or exercising casually unless referring to a designated team position.
A surname.
"The Runner family has lived in this valley for generations."
The word runner comes from the verb "run" combined with a suffix meaning one who performs that action. It entered usage as an agent noun to describe someone or something that runs quickly.