means A friend who accompanies you in social situations, especially to help you approach or impress a potential romantic partner.

from Borrowed straight from military aviation, where a wingman is the pilot who flies just off the leader's wing, guarding their blind spot and covering them in combat. The term took off in World War II-era air forces and was cemented in popular imagination by fighter-pilot culture; by the late 20th century it had glided into civilian slang for the buddy watching your back at the bar instead of in the sky.