Aragorn had many other names and nicknames that he picked up in his life. To see a list of every known name that Aragorn ever had, including those invented and discarded in the original drafts of the LOTR, go here.)
Wingfoot Aragorn met Éomer in the fields of Rohan, and an instant friendship formed, both feeling the honesty and lordliness of the other. Éomer took a risk for his sake, giving him horses, with the promise that one day soon Aragorn would return to Edoras. Aragorn, tracking the Hobbits, followed into Fangorn Forest, where he met the resurrected Gandalf the White. After the restoration of Théoden, he rode to Helm's Deep to fight in the Battle of the Hornburg. There he, alongside his new-found “brother” Éomer, and King Théoden, marshaled the defense against Saruman’s army. Wingfoot is the name Eomer gave Aragorn when he found out how swiftly Aragorn and his two companions had rode to save their friends Merry and Pippin..
When Aragorn chases Merry and Pippin, who were taken by orcs, across the fields of Rohan, he encounters the nephew of King Theoden, Eomer. At first they regard each other with trepidation but when Eomer hears of how fast Aragorn traveled, he is amazed and realizes Aragorn is of noble blood and birth, naming him "Windfoot". (Like Aragorn needs any more names *rolls eyes*).